@article{zhou_luan_chen_yang_liu_liu_xu_sun_murty_2024, title={Exploring the stability, thermodynamic and mechanical properties of zirconium oxides and suboxides under temperature and pressure: A first-principles predictions}, volume={591}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2024.154934}, abstractNote={This study investigates the temperature- and pressure-dependent thermodynamic and mechanical properties of zirconium oxides and suboxides, which is critical for understanding the oxidation/corrosion behaviors of Zr alloys in extreme conditions. Using the first-principles approach, we systematically evaluated the structural, thermodynamic, and mechanical properties of m-ZrO2, t-ZrO2, ZrO, Zr2O, Zr3O, and Zr6O at a wide range of temperatures from 0 to 1600 K and pressures from 0 to 12 GPa. The calculated lattice parameters agree well with the experimental measurements. Moreover, the formation enthalpy and phonon dispersion results indicate that these Zr-O compounds are both thermodynamically and dynamically stable. In particular, ZrO exhibits the largest elastic modulus and hardness among the six Zr-O compounds. The mechanical behaviors vary with temperature and pressure, where m-ZrO2, t-ZrO2, Zr3O, and Zr6O exhibit ductile characteristics, while ZrO and Zr2O undergo a brittle-ductile transition with the change of temperatures and pressures. This work enhances our understanding of the stability of Zr-O phases at different temperatures and pressures, and also provides insights into larger-scale modeling of the microstructural evolution and mechanical properties of Zr alloys during high-temperature oxidation.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Zhou, Hongling and Luan, Baifeng and Chen, Lijun and Yang, Xiaoling and Liu, Congqing and Liu, Xuyang and Xu, Chunrong and Sun, Chao and Murty, Korukonda L.}, year={2024}, month={Apr} } @article{sun_zhou_luan_zhang_zhu_xu_sun_murty_fan_liu_2024, title={In-situ EBSD analysis of hydride phase transformation and its effect on micromechanical behavior in Zircaloy-4 under uniaxial tensile loading}, volume={30}, ISSN={["2214-0697"]}, DOI={10.1016/j.jmrt.2024.05.037}, abstractNote={In this work, hydrogen charged Zircaloy-4 has been investigated under an in-situ electron backscatter diffraction during tensile loading. Aim were, first, to distinguish the hydride phase type and its spatial distribution, second to determine hydride phase transformation (HPT) and orientation relationship (OR) subjected to uniaxial tensile condition, and third to correlate the hydrides evolution and their effect on the micromechanical behavior, such as slip mode activation and lattice rotation, of Zircaloy-4. Apart from the applied stress, the analysis reveals that hydride reorientation is strongly related to temperature and loading mode. We noted that deformation induced δ-ZrH1.5 transformed to γ-ZrH and ε-ZrH2, and the former follows the confirmed OR {0001}α//{111}δ/γ with <11 0>α//<110>δ/γ, while the latter's OR changed to {10 0}α//{121}ε with <11 0>α//<100>ε after HPT. The coexistence of δ-ZrH1.5 and γ-ZrH or ε-ZrH2 is observed, and the main corresponding OR is {111}δ//{111}γ with <121>δ//<121>γ, and {100}δ//{110}ε with <110>δ//<100>ε, respectively. The characterized microstructure and the measured lattice rotation results indicate that HPT delayed cracking in hydride and promoted deformation in parent grains. As the strain increases, the maintenance of hydride-matrix (H-M) coherent interfaces restricts further lattice rotation. HPT accelerates the hydride decomposition ascribed to the intensification of hydrogen diffusion under stress, and the hydride and the H-M interfaces act as priority sites for initiating microcracks. The sequence of HPT depends on the possibility of activated slip mode among grains. These findings contribute to developing the understanding of the HPT and hydrogen embrittlement.}, journal={JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T}, author={Sun, Huanzheng and Zhou, Hongling and Luan, Baifeng and Zhang, Yan and Zhu, Xiaoyong and Xu, Chunrong and Sun, Chao and Murty, Korukonda L. and Fan, Guohua and Liu, Qing}, year={2024}, pages={6653–6667} } @article{yang_chai_tang_wu_tan_murty_2024, title={Novel core-layer-shell structured nano-composite precipitates formed in selective laser melted reduced activation ferritic-martensitic steel}, volume={41}, ISSN={["2352-4928"]}, DOI={10.1016/j.mtcomm.2024.110242}, journal={MATERIALS TODAY COMMUNICATIONS}, author={Yang, Tao and Chai, Linjiang and Tang, Yi and Wu, Yu and Tan, Xiaolian and Murty, Korukonda L.}, year={2024}, month={Dec} } @article{wani_rai_murty_gollapudi_2024, title={Understanding the effect of grain boundary solute segregation on the creep behaviour of thermally stable nanocrystalline materials: a theoretical approach}, ISSN={["1478-6443"]}, DOI={10.1080/14786435.2024.2383252}, abstractNote={In this work, we provide a theoretical framework to evaluate the beneficial effect of solute segregation on the creep behaviour of nanocrystalline materials. We choose copper as the model system and employ the Murdoch and Schuh model to identify Cu–3Zr as a binary system with high thermal stability in its nanocrystalline state. The effect of the segregation of Zr on the grain boundary diffusivity was evaluated using the Hondros and Henderson model. The effect of solute segregation on threshold stress for vacancy emission and absorption at the grain boundaries was evaluated using the Mohamed model. Using these in conjunction with the Bird Mukherjee Dorn equation for creep allowed us to compare the diffusional creep behaviour of nc copper and nc Cu–3Zr. The nc Cu–3Zr system with a grain size of 49 nm demonstrated a higher creep resistance compared to nc Cu bearing a similar grain size. However, the creep resistance of both systems was found to be significantly inferior when compared to the conventional coarse-grained Cu bearing a grain size of 1 μm.}, journal={PHILOSOPHICAL MAGAZINE}, author={Wani, I. and Rai, N. and Murty, K. L. and Gollapudi, S.}, year={2024}, month={Dec} } @article{zhang_chai_qi_wang_wu_pan_teng_murty_2023, title={Microstructures and wear resistance of Zr-4 and N36 alloys subjected to pulsed laser surface remelting}, volume={577}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2023.154284}, abstractNote={Two typical Zr alloys (Zr-4 and N36) for nuclear applications were surface-treated by laser surface remelting (LSR). Electron channeling contrast imaging and electron backscatter diffraction were used to characterize their main microstructure characteristics before and after the LSR, which were also correlated with their hardness and wear resistance. The results show that two surface modification zones with distinct microstructure characteristics appear in both the LSRed Zr alloys: (i) remelting zone (RZ) composed of fine α laths with dense internal nano-twins, and (ii) heat affected zone (HAZ) consisting of blocky α, lath α and second phase particles. The average hardness values of the RZs of Zr-4 and N36 alloys are 254.9 ± 8.5 HV and 269.5 ± 7.9 HV, respectively, ∼30% higher than their substrates. The wear rates of the LSRed Zr-4 and N36 alloys are found to be about 30% and 18% lower than their substrates, respectively, indicating significantly improved wear resistance. Comprehensive analyses reveal that refined grains, solid solution and internal nano-twins generated by ultrafast heating and cooling during the laser treatment have jointly led to the enhanced surface hardness of the LSRed Zr alloys, accounting for their improved wear resistance as well. Compared to the Zr-4 alloy, the refinement of the surface microstructure of the N36 alloy after the LSR treatment is more remarkable, contributing to higher hardness and wear resistance, which is mainly related to the addition of 1 wt.% Nb.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Zhang, Fangli and Chai, Linjiang and Qi, Lan and Wang, Yueyuan and Wu, Lu and Pan, Hucheng and Teng, Changqing and Murty, Korukonda L.}, year={2023}, month={Apr} } @article{yang_chai_wang_li_murty_2023, title={Strength-ductility synergy through tailoring heterostructures of hot-rolled ferritic-martensitic steels containing varying Si contents}, volume={886}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2023.145712}, abstractNote={By utilizing the feature that adding Si is able to effectively increase Ac1 and Ac3 temperatures of ferritic-martensitic (FM) steels, four FM steel sheets with different Si additions (0–1.0 wt%) were prepared by hot rolling at the same intercritical temperature to obtain various heterostructures. Their mechanical properties were evaluated and well correlated with detailed microstructural characteristics revealed by multiple characterization methods. Results show that the 0 Si specimen has a nearly complete martensitic structure; the 0.4 Si specimen consists of ∼23.5 vol% island-like ferrites embedded in martensites exhibiting a typical bi-modal structure (BMS); the 0.7 Si specimen consists of ∼46.8 vol% lamellar ferrites alternating with lamellar martensitic structures corresponding to a typical heterogeneous lamella structure (HLS); the 1.0 Si specimen is mostly comprised of ferrites no longer belonging to typical heterostructures. With increasing Si content, sizes of martensitic laths gradually decrease while the ferritic grains are coarsened. The 0.4 Si and 0.7 Si specimens exhibit high values (∼17 GPa%) of the product of ultimate tensile strength (UTS) and total elongation (TE), demonstrating a good strength-ductility synergy. Comprehensive analyses reveal that the 0.4 Si specimen with BMS exhibits a considerable hetero-deformation induced (HDI) strengthening effect, facilitating the production of the highest UTS (1476.3 MPa), while the 0.7 Si specimen with HLS shows a stronger HDI strain hardening effect leading to a higher TE (12.5%). This study could offer an important reference for designing and processing of FM steels with excellent strength-ductility synergy.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Yang, Tao and Chai, Linjiang and Wang, Hui and Li, Gang and Murty, Korukonda L.}, year={2023}, month={Oct} } @article{zhang_luan_shou_zheng_zhang_liu_murty_2022, title={A quasi in-situ study on the work hardening and softening mechanisms of Ti-33Zr-12Al-6V alloy}, volume={835}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2022.142694}, abstractNote={In this study, a Ti–33Zr–12Al–6V alloy was prepared, and its work hardening and softening mechanisms were investigated via tensile tests conducted at room temperature. The interaction between the dislocations and strain-induced martensite (SIM) results in work hardening; whereas, the shearing of the grain boundaries by the dislocations for entering the adjacent grains results in work softening, which occurs when the logarithmic strains is between 5.8% and 7.6%. Work softening weakened the effect of work hardening; however, through work softening, the workability, which is insufficient in high-strength β-phase titanium alloys, was significantly increased. The microstructure evolution of Ti–33Zr–12Al–6V alloy under different strains was investigated using the quasi in-situ electron backscatter diffraction and scanning electron microscopy methods during the aforementioned tensile tests. The microstructure near the shear bands was observed via transmission electron microscopy using a focused ion beam. First, the {112}<111> slip systems with a high Schmid factor ( SF ) (>0.25) were activated and, subsequently, the {112}<111> with a low SF (≤0.25) and {011}<111> slip systems were activated in most grains during tensile deformation. • The work hardening and softening behaviors were observed at the β-phase Ti–33Zr–12Al–6V high entropy alloy in ambient temperature tensile. • The quasi in-situ SEM and EBSD methods were applied to study the mechanism of work hardening and softening. • {112}<111 and {011}<111>slip systems were activated at different strain of tensile deformation.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Zhang, Fuen and Luan, Baifeng and Shou, Haoge and Zheng, Jiang and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L.}, year={2022}, month={Feb} } @article{alomari_kumar_hawary_murty_2022, title={High Temperature Deformation Behavior of a Fe-25Ni-20Cr (Wt Pct) Austenitic Stainless Steel}, volume={6}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-022-06739-6}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Alomari, Abdullah S. and Kumar, N. and Hawary, Mahmoud and Murty, K. L.}, year={2022}, month={Jun} } @article{chai_xia_murty_gu_fan_yao_2022, title={Revealing Microstructural, Textural, and Hardness Evolution of Ti-6Al-4V Sheet Cooled From Sub beta-Transus Temperature at Different Rates}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-022-06737-8}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Chai, Linjiang and Xia, Jiying and Murty, Korukonda L. and Gu, Xinfu and Fan, Jiangkun and Yao, Zhongwen}, year={2022}, month={Jun} } @article{chai_zhu_hu_murty_guo_chen_ma_zhang_2021, title={A strategy to introduce gradient equiaxed grains into Zr sheet by combining laser surface treatment, rolling and annealing}, volume={196}, ISSN={["1872-8456"]}, DOI={10.1016/j.scriptamat.2021.113761}, abstractNote={A novel strategy combining laser surface treatment, rolling and annealing (LST-RA) to produce gradient equiaxed grains is proposed and verified after applying to pure Zr sheet. Dense high angle boundaries (HABs) are first produced by the laser-induced rapid β→α transformation in the surface layer of pure Zr while a considerable amount of stored energy is then introduced by 50% rolling. During subsequent annealing, the preexisting denser HABs facilitate generating more recrystallization nuclei in the surface layer than in the matrix through the strain induced boundary migration mechanism. This eventually results in a gradient equiaxed grain structure from surface to interior of the pure Zr sheet. Furthermore, the fine-grained surface layer is found to have a weakened texture compared to the coarse-grained matrix.}, journal={SCRIPTA MATERIALIA}, author={Chai, Linjiang and Zhu, Yufan and Hu, Xing and Murty, Korukonda L. and Guo, Ning and Chen, Liang-Yu and Ma, Yanlong and Zhang, Lai-Chang}, year={2021}, month={Apr} } @article{li_luan_liao_liu_chu_wen_murty_liu_2021, title={Effect of friction stir processing and subsequent annealing on microstructure and mechanical properties of a metastable beta-Zr alloy}, volume={822}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2021.141660}, abstractNote={In this work, an effective method to improve the local mechanical properties of β-ZrTiAlV alloy via friction stir processing (FSP) was proposed. A good strength-ductility synergy with high yield strength (896 MPa) and elongation (18.3%) was achieved in the FSPed alloy compared to that of the base material (BM) with low elongation (2.9%) owing to the grain refinement by dynamic recrystallization (DRX) during FSP and the transformation induced plasticity (TRIP) effect caused by deformation-induced α′ martensite transformation. Moreover, FSPed alloy can be further strengthened by annealing treatment. A higher yield strength (1003 MPa) was obtained following 650 °C anneal while a higher ultimate tensile strength (1276 MPa) was acquired in 600 °C annealed samples. The microstructure-properties relationship and underlying deformation mechanisms were also investigated.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Li, Shuo and Luan, Baifeng and Liao, Zhongni and Liu, Zhe and Chu, Linhua and Wen, Shuwen and Murty, K. L. and Liu, Qing}, year={2021}, month={Aug} } @article{tjayadi_kumar_murty_2020, title={Accelerated crack growth experiments of SS304H for dry storage canister in substitute ocean water - Effect of temperature}, volume={23}, ISBN={2352-4928}, DOI={10.1016/j.mtcomm.2020.100929}, abstractNote={Spent nuclear fuels (SNFs) are expected to be stored in dry storage canisters (DSCs) for much longer time than earlier anticipated due to a lack of permanent deep geological repository. As a result, DSCs located in marine environment may undergo chloride induced stress corrosion cracking (SCC) during long-term storage of SNFs. We report here the effect of test temperature on accelerated crack growth experiments carried out on sensitized austenitic stainless steel SS304H in substitute ocean water using fracture mechanics approach. Wedge-opening loading specimens were selected for measurement of crack growth rates using direct-current potential drop technique. Average crack growth rates of 0.975 × 10−10 ± 9.528 × 10-12, 3.258 × 10−10 ± 9.551 × 10-11 and 1.580 × 10-9 ± 2.593 × 10−10 m/s were obtained for 22, 37 and 60 °C, respectively resulting in an activation energy of 60.9 kJ/mol corresponding to diffusion of hydrogen in steel. Intergranular crack propagation was noted along with formation of chromium-rich carbide precipitates at grain boundaries.}, journal={MATERIALS TODAY COMMUNICATIONS}, author={Tjayadi, Leonardi and Kumar, Nilesh and Murty, Korukonda L.}, year={2020}, month={Jun} } @article{joshi_kombaiah_cinbiz_murty_2020, title={Characterization of stress-rupture behavior of nuclear-grade C26M2 FeCrAl alloy for accident-tolerant fuel cladding via burst testing}, volume={791}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2020.139753}, abstractNote={Abstract FeCrAl alloys demonstrate excellent high-temperature oxidation resistance compared to zirconium alloys used in LWRs. FeCrAl C26M2 has been down-selected as one of the candidate ATF cladding materials for Gen II LWRs. This study investigates the stress-rupture behavior of the nuclear-grade FeCrAl C26M2 tubing in the temperature range of 753-923 K. Rupture time and uniform strain at rupture were determined as a function of the temperature and applied stress using burst tests. The rupture data was found to obey the Larson-Miller Parameter and the Monkman-Grant relationship. Furthermore, the stress exponent (n) and the activation energy (QC) at lower stresses were determined as 4.4 ± 0.3 and 289 ± 25 kJ/mol, respectively, confirming power-law behavior. Above the normalized stress (σ/E) of 2 × 10−3, the power-law creep transited into the power-law breakdown regime. The steady-state deformation microstructure was examined using transmission electron microscopy (TEM) to detect the rate-controlling creep mechanism(s). Observation of sub-grains with dislocations at the boundaries in the power-law regime along with a stress exponent of 4.4 suggests dislocation climb as the rate-controlling mechanism. Two different fracture modes were observed: the tubing failed either by direct open-up or small crack and pinhole formation. The outcome of this study would provide essential data for the development of informative mesoscale deformation models paving way for discovery of new creep resistant alloys.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Joshi, P. and Kombaiah, B. and Cinbiz, M. N. and Murty, K. L.}, year={2020}, month={Jul} } @article{dai_xia_chai_murty_guo_daymond_2020, title={Correlation of microstructural, textural characteristics and hardness of Ti-6Al-4V sheet beta-cooled at different rates}, volume={55}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-020-04603-9}, number={19}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Dai, Jiahong and Xia, Jiying and Chai, Linjiang and Murty, Korukonda L. and Guo, Ning and Daymond, Mark R.}, year={2020}, month={Jul}, pages={8346–8362} } @article{alsmadi_murty_2021, title={Effect of Strain Range on High Temperature Creep-Fatigue Behaviour of Fe-25Ni-20Cr (wt.%) Austenitic Stainless Steel (Alloy 709)}, volume={38}, ISSN={["1878-6413"]}, url={https://doi.org/10.1080/09603409.2020.1859310}, DOI={10.1080/09603409.2020.1859310}, abstractNote={ABSTRACT Since the preliminary data suggest that Fe-25Ni-20Cr austenitic stainless steel (Alloy 709) is an excellent candidate as a structural material for high-temperature applications such as Sodium-cooled Fast Reactor (SFR), the effect of strain range on creep-fatigue interaction of the Alloy 709 is investigated by conducting strain-controlled creep-fatigue tests with tensile hold times of 0, 600, 1,800 and 3,600 s at strain ranges varying from 0.6% to 1.2% at 750°C and 2 × 10−3 s−1 strain rate. Strain-controlled fatigue tests were performed at strain ranges from 0.3% to 2.5% at 750°C and 2 × 10−3 s−1 strain rate. The predicted fatigue life of Alloy 709 shows a better correlation with the characteristic slopes predictive method. With increasing strain range at a given hold time, the number of failure cycles decreases until saturation. The fractography of the deformed samples exhibited increased number of cracks with strain range along with M23C6 precipitates and high dislocation density.}, number={1}, journal={MATERIALS AT HIGH TEMPERATURES}, publisher={Informa UK Limited}, author={Alsmadi, Zeinab Y. and Murty, K. L.}, year={2021}, month={Jan}, pages={47–60} } @article{zhang_luan_chu_wen_zhang_wang_wu_murty_2021, title={Effects of composition on phase stabilities and elastic properties in TiZrAlV alloys : Experiments and first-principles calculations}, volume={863}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2020.158054}, abstractNote={Phase stability and the elastic properties of α, β, α" and ω phases in four different component TiZrAlV alloys were studied by first-principles calculations and experiments. The results of Differential Scanning Calorimetry (DSC) and X-ray Diffractometer (XRD) showed that α, β, α" and ω phases could be stabilized in four alloys except β phase in TZA8 alloy. Varied compositions and phases in the alloys lead to different Young's modulus E. First-principles calculations were used to verify the experimental results in the four TiZrAlV alloys. Four atomic configurations of TiZrAlV systems with β, α", α and ω phases were obtained using approximate simplified atomic ratios. These 16 models were calculated to investigate their phase stabilities and elastic properties by means of electronic structure, formation enthalpy ΔHf and elastic properties. The density of states (DOS) of β phase in TZA8 alloy without pseudogap near Fermi level (EF) suggested that β phase was unlikely to exist in the TZA8 alloy, which agreed with the experiment results. From the results of energy calculations, β-phase was found to be more structurally stable compared to α, α" and ω phases in TZA12V6 and TZA12V4 alloys. α"-phase in alloys TZA14V8, TZA12V6 and TZA12V4 and β-phase in TZA8 alloy had the lowest stability. The results of elastic properties showed that Young's modulus was affected by alloy composition and phase, and β-phase had the characteristics of lower Young's modulus and better plasticity than other phases in the TiZrAlV alloys. The results of experiments and first-principles calculations manifested that the compositions affected the phase stabilities and the elastic properties of the TiZrAlV alloys.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Zhang, Fuen and Luan, Baifeng and Chu, Linhua and Wen, Shuwen and Zhang, Shuyan and Wang, Yuhui and Wu, Lailei and Murty, Korukonda L.}, year={2021}, month={May} } @article{alsmadi_murty_2021, title={High-temperature effects on creep-fatigue interaction of the Alloy 709 austenitic stainless steel}, volume={143}, ISSN={["1879-3452"]}, url={https://doi.org/10.1016/j.ijfatigue.2020.105987}, DOI={10.1016/j.ijfatigue.2020.105987}, abstractNote={High-temperature creep-fatigue behavior of the Alloy 709 is investigated by performing strain-controlled creep-fatigue tests at 650 °C and 750 °C with tensile hold times of 0, 60, 600, 1,800 and 3,600 s at 1% strain range and strain rate of 2 × 10−3 s−1. Results revealed that creep-fatigue life at 650 °C fluctuates due to Dynamic Strain Aging (DSA) during hold periods. Linear damage summation (LDS) was employed to construct the creep-fatigue interaction diagram of the alloy at different loading conditions. An increased density of cracks and creep cavities is observed at 750 °C with less dislocation density compared to 650 °C.}, journal={INTERNATIONAL JOURNAL OF FATIGUE}, publisher={Elsevier BV}, author={Alsmadi, Zeinab Y. and Murty, K. L.}, year={2021}, month={Feb} } @article{xiang_chai_wang_wang_guo_ma_murty_2020, title={Microstructural characteristics and hardness of CoNiTi medium-entropy alloy coating on pure Ti substrate prepared by pulsed laser cladding}, volume={849}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2020.156704}, abstractNote={A ternary CoNiTi medium-entropy (MEA) alloy coating was successfully fabricated on pure Ti substrate by utilizing pulsed laser cladding. Phase constitutions and microstructural characteristics of the coating were analyzed by combined use of X-ray diffraction, electron channeling contrast imaging, secondary electron imaging, energy dispersive spectroscopy and electron backscatter diffraction techniques. Results show that three zones with distinct microstructures are formed after the pulsed laser cladding treatment: cladding zone (CZ), bonding zone (BZ) and heat-affected zone (HAZ). Dendritic (BCC solid-solution phase)-interdendritic (Ti2Ni type phase) structures are formed in the CZ with many nanoparticles (Ti2Co type phase) dispersed inside the interdendritic structures. The BZ consists of fine acicular grains while the HAZ below the BZ is composed of irregular-shaped bulk grains. Hardness measurements reveal that hardness of the MEA coating reaches 571 ± 46 H V, which is ∼5 times that of the substrate (114 ± 4 H V). Comprehensive analyses show that such high hardness can be attributed to the combined contributions from solid-solution hardening of the BCC phase and second-phase hardening from the Ti2Ni and Ti2Co type intermetallic compounds.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Xiang, Kang and Chai, Linjiang and Wang, Yueyuan and Wang, Hao and Guo, Ning and Ma, Yanlong and Murty, Korukonda L.}, year={2020}, month={Dec} } @article{tjayadi_kumar_murty_2020, title={Stress Corrosion Cracking Behavior of Austenitic Stainless Steel SS304 for Dry Storage Canisters in Simulated Sea-Water}, ISBN={["978-3-030-36295-9"]}, ISSN={["2367-1696"]}, DOI={10.1007/978-3-030-36296-6_133}, abstractNote={A number of recent studies have suggested that dry storage canisters (DSCs) made of austenitic stainless steelAustenitic stainless steel SS304 to store spent nuclear fuel located along coastal region may undergo stress corrosion crackingStress corrosion cracking (SCCSCC ) if their useful life is extended due to lack of a permanent underground burial repository. It, therefore, becomes necessary to understand SCCSCC behavior of SS304 in marine environment. We report here our results on SCCSCC of SS304H in simulated sea-water using fracture mechanicsFracture mechanics approach as a function of temperature. The average crack growth ratesCrack growth rates were noted to be 0.975 × 10−10 ± 9.528 × 10−12, 3.258 × 10−10 ± 9.551 × 10−11, and 1.580 × 10−9 ± 2.593 × 10−10 m/s at 22, 37, and 60 °C, respectively. The activation energyActivation energy of the crack growth process was estimated to be 60.9 kJ/mol corresponding to diffusion of hydrogen in steelSteel . Optical microscopyMicroscopy revealed intergranular nature of the crack growth.}, journal={TMS 2020 149TH ANNUAL MEETING & EXHIBITION SUPPLEMENTAL PROCEEDINGS}, author={Tjayadi, Leonardi and Kumar, Nilesh and Murty, Korukonda L.}, year={2020}, pages={1431–1442} } @article{li_luan_chu_zhang_yuan_liu_murty_liu_2020, title={Twinning behaviors and grain refinement mechanisms during friction stir processing of Zr alloy}, volume={163}, ISBN={1873-4189}, DOI={10.1016/j.matchar.2020.110277}, abstractNote={The twinning behaviors and grain refinement mechanisms during friction stir processing (FSP) of Zircaloy-4 were studied. The main deformation mode changed due to temperature and strain gradient existed in different regions of FSP sample. The 101¯2 and 101¯1 twins were activated successively in thermo-mechanically affected zone (TMAZ) but reduced rapidly and replaced by dislocations slip in stir zone (SZ) because of the elevated temperature and decreased grain size. Accordingly, the grain refinement mechanisms also varied with the deformation modes. A new recrystallization mechanism, twinning induced dynamic recrystallization (TDRX) was proposed for the first time in FSPed Zr alloy, which resulted in grain refinement in TMAZ. The occurrence of TDRX included the formation of slipped 101¯2 twin boundaries and the transformation of 101¯1 twins into high angle grain boundaries (HAGBs); these were attributed to the interaction between twins and dislocations. In contrast, continuous dynamic recrystallization (CDRX) related to dislocations slip at higher temperatures dominated the process of grain refinement in SZ, and finally the ultrafine grains with average size of ~1 μm were obtained.}, journal={MATERIALS CHARACTERIZATION}, author={Li, Shuo and Luan, Baifeng and Chu, Linhua and Zhang, Xinyu and Yuan, Gaihuan and Liu, Riping and Murty, K. L. and Liu, Qing}, year={2020}, month={May} } @article{liao_luan_zhang_liu_murty_liu_2020, title={A multi-deformation mechanisms assisted metastable beta-ZrTiAlV alloy exhibits high yield strength and high work hardening rate}, volume={816}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2019.152642}, abstractNote={A metastable β-51.1Zr-40.2Ti-4.5Al-4.2V (wt.%) alloy with both TRIP and TWIP effects, exhibiting high yield strength of 800 MPa, high work hardening rate and good total elongation close to 17.5% was reported. The solid solution strengthening of high content of Ti and the special initial deformation mechanisms result in the outstanding yield strength. Microstructural analyses show that the dominant deformation mechanisms transformed from deformation-induced β→α′ martensitic transformation and kinking band at low strain to deformation-induced β→α′ martensitic transformation, widening and merging of α′ martensite, and {101‾1}α′ twinning at high strain. Changes in the dominant deformation mechanisms at different deformation stages lead to changes in special boundaries, resulting in a substantial high work hardening rate (2000–5440 MPa) until 10% strain. In addition, the reason for the TWIP effect in present alloy is internal {101‾1}α′ twin, which is different from that of the previously reported twins.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2020}, month={Mar} } @article{joshi_tillman_kumar_murty_cinbiz_2020, title={Biaxial Creep Behavior of Nb-Modified Zircaloys}, volume={206}, ISSN={["1943-7471"]}, DOI={10.1080/00295450.2019.1674581}, abstractNote={Abstract Zirconium-niobium (Zr-Nb) alloys are used as cladding materials to encapsulate radioactive fuel in nuclear reactors. They possess excellent corrosion resistance at high temperatures making it possible to achieve high fuel burnup, directly increasing the thermal efficiency of the reactor. While they are commonly used in recrystallized (Rx) form in boiling water reactors, there is a need to understand the effect of cold work and stress relief (CWSR) on the biaxial creep characteristics of these materials due to their use in pressurized water reactors. In this study, the biaxial creep behaviors of as-received Zr-Nb alloys, HANA and Zirlo®, have been investigated at 500°C and 400°C, respectively, using internally pressurized tubing superimposed with axial load under varied hoop σθ to axial σz stress ratios of 0 to 2 while monitoring both the axial and hoop strains using a linear variable displacement transformer and a laser telemetric extensometer, respectively. The crystallographic textures and creep loci of these as-received Zr-Nb alloys have been evaluated to correlate with the previous studies on recrystallized HANA4 and CWSR Zircaloy-4. The creep locus of HANA4 was found to be unaffected by initial state (CWSR or Rx) and showed close correspondence to planar isotropy while the creep locus of CWSR Zirlo exhibited more resistance to axial deformation than diametrical as per CWSR Zircaloy-4 reported earlier. These differences are shown to arise from grain-shape anisotropy of the CWSR Zirlo and Zircaloy-4. The simulated creep loci using crystallite-orientation distribution functions in conjunction with prism slip models showed excellent agreement with experimental results.}, number={5}, journal={NUCLEAR TECHNOLOGY}, author={Joshi, Pratik and Tillman, Micah and Kumar, Nilesh and Murty, Korukonda and Cinbiz, Nedim}, year={2020}, month={May}, pages={706–716} } @article{alsmadi_alomari_kumar_murty_2020, title={Effect of hold time on high temperature creep-fatigue behavior of Fe-25Ni-20Cr (wt.%) austenitic stainless steel (Alloy 709)}, volume={771}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2019.138591}, abstractNote={To understand high temperature creep-fatigue interaction of the Alloy 709, strain-controlled low-cycle fatigue (LCF) tests were performed at strain ranges varying from 0.3% to 1.2% with fully reversible cycle of triangular waveform at 750 °C. In addition, different hold times of 60, 600, 1800 and 3600 s were introduced at the maximum tensile strain to investigate the effect of creep damage on the fatigue-life at strain range of 1% at 750 °C. The creep-fatigue life and the number of cycles to macro-crack initiation and failure are found to decrease with increasing hold time indicating higher crack initiation and growth rates. Creep-fatigue life is evaluated by a linear summation of fractions of cyclic and creep damages according to ASME code. The fractographs of the samples deformed at 1% strain range indicated that fatigue might have been the dominant mode of deformation whereas, for the samples deformed at the same strain range with different hold times, both fatigue and creep have contributed to the overall deformation and fracture of the alloy.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Alsmadi, Zeinab Y. and Alomari, Abdullah and Kumar, N. and Murty, K. L.}, year={2020}, month={Jan} } @article{kombaiah_sarkar_murty_2019, title={Effect of hydriding on the creep behavior of HANA-4 zirconium alloy}, volume={767}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2019.138435}, abstractNote={HANA-4 (High Temperature Alloys for Nuclear Applications) is Zr-1.5 Nb alloy developed by the Korea Atomic Energy Research Institute for advanced nuclear fuel cladding applications. In this work, the effect of hydriding on the biaxial creep behavior of HANA-4 alloy was studied through internal pressurization of closed end tubes by applying a range of hoop stresses (27 MPa–156 MPa) at two temperatures: 400 °C and 500 °C. Test specimens included two HANA-4 tubes hydrided using an electrolytic method with 387 ppm and 715 ppm of hydrogen, respectively, and non-hydrided HANA-4 tubes as the control sample. To understand the effect of hydriding on creep, steady state creep rates and stress exponents of the specimens were determined from the creep data. Furthermore, in situ X-ray diffraction (XRD) experiments were conducted on the hydrided HANA-4 specimens during heating to detect the dissolution limit of the hydride phase. On examining the results of the creep tests and the XRD experiments collectively, it is concluded that hydrogen while being fully dissolved into the solid solution enhances the creep rate of HANA-4 tubes. On the other hand, hydrogen present, even partially, as hydride phase at the creep test temperature lowers the creep rate. The rate controlling mechanisms of creep in HANA-4, however, remained unchanged as noted from similar stress exponents of the hydrided and non-hydrided specimens. The rationale behind these observations is explained based up on models predicting the interaction of dislocations with hydrogen and hydride phase.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Kombaiah, Boopathy and Sarkar, Apu and Murty, Korukonda Linga}, year={2019}, month={Nov} } @article{liao_luan_zhang_liu_murty_liu_2020, title={Effect of varying a phase fraction on the mechanical properties and deformation mechanisms in a metastable beta-ZrTiAlV alloy}, volume={772}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2019.138784}, abstractNote={We systematically investigated the effects of varying α phase fraction on the mechanical properties and deformation mechanisms in a metastable β-51.1Zr-40.2Ti-4.5Al-4.2V (wt. %) alloy containing mixed α + β phase. Various heat treatments from single β phase regime to dual α+β phase regime were imposed in order to alter the volume fraction of α phase. The results show that the triggering stress increases and the total elongation decreases with the increasing α phase fraction. As the α phase fraction increases, the work hardening rate curve changes from an obvious parabolic evolution to a monotonically decreasing evolution and the work hardening effect is gradually reduced. Co-existence deformation mechanisms of kink bands, deformation-induced α′ martensite and {101‾1}α′ mechanical twinning were detected in low α phase fraction samples but not in high α phase fraction sample. In intermediate α phase fraction sample, only deformation-induced α′ martensite was activated. For the first time, the effects of α phase fraction on the deformation-induced α′ martensite, {101‾1}α′ mechanical twinning and kink bands were observed in metastable β-Zr alloy. These effects of varying α phase fraction on the mechanical properties and deformation mechanisms are discussed based on the β stability and the β domain size.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2020}, month={Jan} } @article{chai_xiang_xia_fallah_murty_yao_gan_2019, title={Effects of pulsed laser surface treatments on microstructural characteristics and hardness of CrCoNi medium-entropy alloy}, volume={99}, ISSN={["1478-6443"]}, DOI={10.1080/14786435.2019.1649499}, abstractNote={ABSTRACT A hot-swaged/annealed CrCoNi medium-entropy alloy (MEA) was surface-treated by pulsed laser at two different powers (400 and 200 W). Microstructural characteristics of the laser-modified zones were characterised and analysed by energy dispersive spectroscopy, electron backscatter diffraction and electron channelling contrast imaging techniques. Results show that melting and rapid solidification occur on the surfaces of both laser-treated specimens, and profuse annealing twins existing in the initial microstructures are essentially eliminated in the melting zone (MZ) with plentiful low-angle boundaries appearing. Meanwhile, the initial equiaxed grains are replaced by new grains in the MZ with either granular or columnar appearance (in the 2D cross-sectional views). These grains are comprised of fine cellular structures with relatively uniform sizes (∼1–2 μm in width/diameter), the formation of which is related to the segregation of Cr during solidification. With the laser power decreasing from 400 to 200 W, the volume of the MZ and grain sizes in its interior are reduced. This is due to less heat supply and faster cooling caused by reducing the laser power. Hardness tests reveal that the surfaces of both the laser-treated specimens are slightly softened (by 10–20%), and quantitative analyses suggest that this is mainly related to grain coarsening and the disappearance of annealing twins in the MZ.}, number={24}, journal={PHILOSOPHICAL MAGAZINE}, author={Chai, Linjiang and Xiang, Kang and Xia, Jiying and Fallah, Vahid and Murty, Korukonda L. and Yao, Zhongwen and Gan, Bin}, year={2019}, month={Dec}, pages={3015–3031} } @article{wang_luan_xin_xing_murty_cayron_liu_2019, title={Experimental and theoretical investigation of crystallography and variant selection during massive transformation in Zr alloy}, volume={99}, ISSN={["1478-6443"]}, DOI={10.1080/14786435.2019.1574408}, abstractNote={ABSTRACT Massive transformation, as a non-conventional solid-state phase transformation mode, is scarcely observed in metals with hexagonal closed packed (HCP) structure, especially in Zr and its alloys. In this study, however, we report the massive transformation in a Zr-1.0Cr-0.4Fe alloy after conventional β-quenching. It is shown that the necessary condition to induce the occurrence of massive transformation requires an appropriate composition and cooling rate of the alloy to be simultaneously within reasonable ranges. We combine the electron backscatter diffraction (EBSD) and crystallographic reconstruction techniques to systematically assess the orientation relationship between massive grain (αm) and its β parent grain. It is demonstrated that, similar to martensitic transformation, the orientation between αm and β parent grain during massive transformation satisfies Burgers orientation relationship, i.e. and . Furthermore, a statistical analysis of EBSD data shows that variant selection occurs during massive transformation due to pre-existing β-β grain boundary. Based on mathematical theory and crystallographic calculations, we further explore the detailed mechanisms of variant selection during massive transformation.}, number={10}, journal={PHILOSOPHICAL MAGAZINE}, author={Wang, J. M. and Luan, B. F. and Xin, R. L. and Xing, Q. F. and Murty, K. L. and Cayron, C. and Liu, Q.}, year={2019}, month={May}, pages={1163–1183} } @article{tjayadi_kumar_murty_2019, title={Fracture Mechanics-Based Study of Stress Corrosion Cracking of SS304 Dry Storage Canister for Spent Nuclear Fuel}, ISSN={["2367-1696"]}, DOI={10.1007/978-3-030-05861-6_106}, abstractNote={Many independent spent fuel storage installations (ISFSI) are located along the coastal regions in the US and the dry storage canisters consisting of spent nuclear fuels are envisioned to undergo chloride-induced stress corrosionCorrosion cracking (SCCSCC ) in heat-affected zoneHeat-affected zone (HAZ) . In the present study, we have investigated SCCSCC behavior of sensitized SS304H under substitute ocean water at room temperature using wedge opening loading (WOL) specimens. The alloy was sensitized at 600 °C for 215 h followed by microstructural characterizationCharacterization . The crack growth during the test was monitored using direct current potential dropPotential drop technique. The crack growthCrack growth rate for the SS304H alloy was within the same order of magnitude as reported in literature for SS304 alloy under chloride environment.}, journal={TMS 2019 148TH ANNUAL MEETING & EXHIBITION SUPPLEMENTAL PROCEEDINGS}, author={Tjayadi, Leonardi and Kumar, Nilesh and Murty, Korukonda L.}, year={2019}, pages={1089–1097} } @article{dai_zeng_li_chai_zheng_wu_murty_guo_2019, title={Misorientation characteristics and textural changes induced by dense twins in high-purity Ti sheet after small strain rolling}, volume={62}, ISSN={["1869-1900"]}, DOI={10.1007/s11431-019-9555-9}, number={11}, journal={SCIENCE CHINA-TECHNOLOGICAL SCIENCES}, author={Dai, JiaHong and Zeng, LingGuo and Li, ZhiJun and Chai, LinJiang and Zheng, ZhiYing and Wu, Hao and Murty, K. L. and Guo, Ning}, year={2019}, month={Nov}, pages={1968–1975} } @article{alomari_kumar_murty_2019, title={Serrated yielding in an advanced stainless steel Fe-25Ni-20Cr (wt%)}, volume={751}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2019.02.023}, abstractNote={Understanding serrated yielding behavior resulting from dynamic strain aging (DSA) is essential for design and safety considerations. In this work, uniaxial tensile tests were carried out at temperatures ranging from 298 to 1073 K and strain rates 10−5 – 10−3 s−1 followed by microstructural examination of Fe-25Ni-20Cr (wt%) austenitic stainless steel (Alloy 709), a candidate structural material for Sodium-cooled Fast Reactors. Serrated yielding was found to occur in this alloy in two temperature regimes; low-temperature serrated flow (LT-SF) from 498 to 648 K and high-temperature serrated flow (HT-SF) from 648 to 973 K (depending on the strain rate) with activation energies of 103 ± 13 kJ/mole and 204 ± 11 kJ/mole respectively. The critical strain for the occurrence of serrations was found to increase with strain rate as an exponential function with exponent (m + β) of 0.78 ± 0.1 and 1.56 ± 0.2 for the LT-SF and HT-SF regimes respectively. Based on the activation energies and m + β values, diffusion of interstitial atoms has been suggested to be responsible for serrated flow in the LT-SF regime while Cr atom migration was inferred to be responsible for DSA in the HT-SF regime. Manifestations of DSA in the Alloy 709 were observed including peaks and/or plateaus in flow stresses along with negative strain rate sensitivity at intermediate temperatures. However, no loss in ductility was observed within DSA regime attributed to the relatively high work hardening rate and strain-hardening exponent. The samples deformed in DSA regime showed planar substructure while equiaxed subgrains formed at higher temperatures. The fraction of low angle grain boundaries after deformation exhibited a valley at intermediate temperatures believed to be another manifestation of the DSA.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Alomari, Abdullah S. and Kumar, N. and Murty, K. L.}, year={2019}, month={Mar}, pages={292–302} } @article{liao_luan_zhang_liu_murty_liu_2019, title={The effects of increasing deformation strain on the microstructural evolution of a metastable beta-Zr alloy}, volume={800}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2019.05.334}, abstractNote={In this study, we investigated the morphology evolution of deformation-induced α', α″ martensite and retained β phase with increasing deformation strain in metastable β-Zr-43.2Ti-4.5Al-4.2V (wt. %) alloy by ex-situ and regular compression tests. Three types of deformation-induced α' martensite have been observed for the first time during deformation, namely, twinned α' martensite, untwinned α' martensite and paired α' martensite. Transitions in morphology of twinned α' martensite from thin plate to twinned plate and to widened twinned plate, eventually to {101¯2} twin-related domains and of untwinned α' martensite from thin plate to widened plate to domain have been observed with increasing deformation strains. The paired α' martensite is undergone a process in which the α' martensite impacted grain boundaries stimulating the nucleation of new α' martensite in neighboring grains, and then leading to martensite growth on both sides grow simultaneously. With progressive deformation, the nano-size deformation-induced α″ martensite changes from long thin plate to ladder-shaped plate to 90° rotation domains. The morphology evolution of untwinned α' martensite, paired α' martensite and α″ martensite are mainly related to the self-accommodation mechanism, while the morphology evolution of twinned α' martensite is mainly related to the plastic accommodation mechanism. The average hardness increased with increase in deformation strains, owing to the martensitic transformation strengthening along with dislocation multiplication strengthening.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2019}, month={Sep}, pages={208–218} } @article{sarkar_murty_2018, title={Anisotropic grain growth kinetics in nanocrystalline nickel}, volume={98}, ISSN={["1362-3036"]}, DOI={10.1080/09500839.2019.1583391}, abstractNote={ABSTRACT Intriguing properties exhibited by nanocrystalline metals, including a high level of mechanical strength, arise from their nanometer-scale grain sizes. It is critical to determine the evolution of grain size of nanocrystalline materials at elevated temperature, as this process can drastically change the mechanical properties. In this work, a nanocrystalline Ni foil with grain size ∼ 25 nm was annealed in situ in an X-ray diffractometer. X-ray diffraction peaks were analysed to determine the grain growth kinetics. The grain growth exponents obtained were ∼ 2–4 depending upon the crystallographic direction, indicating the anisotropic nature of the grain growth kinetics.}, number={11}, journal={PHILOSOPHICAL MAGAZINE LETTERS}, author={Sarkar, Apu and Murty, K. L.}, year={2018}, month={Nov}, pages={494–501} } @article{alomari_kumar_murty_2019, title={Creep Behavior and Microstructural Evolution of a Fe-20Cr-25Ni (Mass Percent) Austenitic Stainless Steel (Alloy 709) at Elevated Temperatures}, volume={50A}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-018-5044-y}, number={2}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Alomari, Abdullah S. and Kumar, N. and Murty, K. L.}, year={2019}, month={Feb}, pages={641–654} } @article{zeng_luan_wang_zhang_liu_murty_liu_2018, title={Effect of initial orientation on dynamic recrystallization of a zirconium alloy during hot deformation}, volume={145}, ISSN={["1873-4189"]}, DOI={10.1016/j.matchar.2018.09.008}, abstractNote={The present study investigated the influence of the initial orientation on the dynamic recrystallization (DRX) behavior of a Zr-1Sn-0.3Nb alloy. A hot-rolled and annealed Zr sheet was compressed along two directions: along the normal direction so that the grains' ⟨c⟩-axis was nearly parallel to the loading direction (0° sample) and along the transverse direction so that the grains' ⟨c⟩-axis was nearly perpendicular to the loading direction (90° sample). The samples were compressed at 700 °C at a strain rate of 1 s−1. The microstructures at different strains were characterized by the electron backscatter diffraction (EBSD) technique, and conventional dislocation analysis using transmission electron microscope (TEM) was performed. A threshold value of grain orientation spread (GOS) equaled to 5° was used to distinguish the dynamically recrystallized grains from the deformed matrix. The results revealed that the DRX behavior strongly depended on the initial orientation. The Schmid factor analysis and TEM observation confirmed that pyramidal ⟨c + a⟩ slip operated from the first stage of deformation in the 0° sample but not in the 90° sample. For the 0° sample, in the early and medium stages of deformation, due to the high stored energy caused by the operation of pyramidal ⟨c + a⟩ slip, DDRX was mainly contributed to the formation of new fine grains. However, in the later stage of deformation, the DRX mechanism changed from DDRX to CDRX. In the 90° sample, although DDRX featured by grain boundary bulging occurred, the main DRX mechanism was CDRX in the whole deformation processing. Moreover, texture induced hardening in the early stage of deformation hides the softening induced by DDRX.}, journal={MATERIALS CHARACTERIZATION}, author={Zeng, Qinghui and Luan, Baifeng and Wang, Yuhui and Zhang, Xinyu and Liu, Riping and Murty, Korukonda Linga and Liu, Qing}, year={2018}, month={Nov}, pages={444–453} } @article{alomari_kumar_murty_2018, title={Enhanced ductility in dynamic strain aging regime in a Fe-25Ni-20Cr austenitic stainless steel}, volume={729}, ISSN={0921-5093}, url={http://dx.doi.org/10.1016/J.MSEA.2018.05.060}, DOI={10.1016/J.MSEA.2018.05.060}, abstractNote={Contrary to the commonly observed embrittlement during dynamic strain aging, we report in this note distinct enhancement in ductility in a Nb-containing and nitrogen stabilized Fe-25(wt%)Ni-20Cr austenitic stainless steel (Alloy 709) at temperatures from 623 K to 873 K at 10−4 s−1 where serrated flow is noted. This observation is rationalized in terms of the influence of strain hardening parameters and strain rate sensitivity on uniform elongation and ductility respectively.}, journal={Materials Science and Engineering: A}, publisher={Elsevier BV}, author={Alomari, Abdullah S. and Kumar, N. and Murty, K.L.}, year={2018}, month={Jun}, pages={157–160} } @article{chai_chen_zhi_murty_chen_yang_2018, title={Nanotwins induced by pulsed laser and their hardening effect in a Zr alloy}, volume={748}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2018.03.126}, abstractNote={A pulsed laser was employed to treat a Zr-2.5Nb alloy with laser-induced microstructures (especially dense nanotwins) characterized by electron channeling contrast imaging (ECC) imaging and electron backscatter diffraction (EBSD) techniques. Hardening effect of the nanotwins was derived by analyzing hardness contributions from various microstructural factors modified by the pulsed laser treatments (PLT). Results show that dense nanotwins, that are difficult to introduce into Zr alloys by conventional thermo-mechanical methods, can be readily produced by the PLT at laser powers of 50 and 100 W. The twinning system is determined to be the compressive type of {10–11}〈10–12〉 by orientation analyses using EBSD. After the PLT, specimen hardness is markedly increased, which could be attributed to not only grain refinement and solid solution of Nb but more considerably to the abundance of the {10–11} nanotwins, demonstrating their strong hardening effect.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Chai, Linjiang and Chen, Ke and Zhi, Yan and Murty, Korukonda L. and Chen, Liang-Yu and Yang, Zhinan}, year={2018}, month={Jun}, pages={163–170} } @article{liao_luan_zhang_xing_liu_murty_liu_2019, title={Study of deformation mechanisms in a metastable beta Zr alloy during compression}, volume={237}, ISSN={["1873-4979"]}, DOI={10.1016/j.matlet.2018.11.043}, abstractNote={The deformation mechanisms in a metastable β-48.1Zr-43.2Ti-4.5Al-4.2V (wt%) alloy after room-temperature compression to ∼6% strain were investigated. The results indicated that the alloy deforms primarily by deformation-induced β → α′ martensitic transformation and 101¯2<101¯1> twinning, and limited deformation-induced β → α″ martensitic transformation. The 101¯2<101¯1> twinning was formed within the α′ plate to accommodate the local plastic deformation strain generated in α′ martensite plate during compression. Such a combination of deformation mechanisms were observed in metastable β Zr or Ti alloys for the first time, which can aid future development of superior β Zr alloys displaying a potentially combination of transformation-induced plasticity (TRIP) and transformation twinning-induced plasticity (TWIP) effects.}, journal={MATERIALS LETTERS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Xing, Qingfeng and Liu, Riping and Murty, K. L. and Liu, Qing}, year={2019}, month={Feb}, pages={172–175} } @inbook{kumar_alomari_murty_2018, title={Understanding Creep-Fatigue Interaction in Fe-25Ni-20Cr (wt%) Austenitic Stainless Steel}, ISBN={9783319950525 9783319950532}, ISSN={2191-5644 2191-5652}, url={http://dx.doi.org/10.1007/978-3-319-95053-2_5}, DOI={10.1007/978-3-319-95053-2_5}, abstractNote={Gen-IV nuclear reactors require materials to operate under much harsher conditions necessitating the development of advanced structural materials. Sodium-cooled Fast Reactor (SFR) is a Gen-IV nuclear reactor with a high level of technology readiness. Alloy 709, Fe-25Ni-20Cr (wt%) alloyed with Nb and stabilized with nitrogen, is an advanced austenitic stainless steel having promising set of properties for SFRs. However, the creep-fatigue deformation behavior is unknown for this alloy. This work focuses on evaluating creep-fatigue interaction in this alloy. We report here a creep-fatigue study conducted at 750 °C using triangular waveform following the ASTM standard E2714–13 at 0.1 Hz frequency. The creep-fatigue tests were conducted in strain-controlled mode where strain amplitudes of 0.2% and 0.5% were used. The microstructural examination in as-received and post-deformation conditions were carried out using scanning and transmission electron microscopes. The creep-fatigue lives at 0.2% and 0.5% strain amplitudes were 17,416 and 526 cycles, respectively. The comparison of the TEM micrographs between as-received and creep-fatigue deformed at 0.5% strain amplitude showed higher dislocation density and loosely defined subgrains in the deformed alloy. The fractographs indicated that for the samples deformed at 0.2% strain amplitude, fatigue might have been the dominant mode of deformation whereas for the sample deformed at 0.5% strain amplitude, fatigue and creep both might have contributed to the overall deformation of the alloy.}, booktitle={Challenges in Mechanics of Time-Dependent Materials, Volume 2}, publisher={Springer International Publishing}, author={Kumar, N. and Alomari, A. and Murty, K. L.}, year={2018}, month={Aug}, pages={33–38} } @article{kumar_alomari_murty_2018, title={Understanding thermally activated plastic deformation behavior of Zircaloy-4}, volume={504}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2018.03.031}, abstractNote={Understanding micromechanics of plastic deformation of existing materials is essential for improving their properties further and/or developing advanced materials for much more severe load bearing applications. The objective of the present work was to understand micromechanics of plastic deformation of Zircaloy-4, a zirconium-based alloy used as fuel cladding and channel (in BWRs) material in nuclear reactors. The Zircaloy-4 in recrystallized (at 973 K for 4 h) condition was subjected to uniaxial tensile testing at a constant cross-head velocity at temperatures in the range 293 K–1073 K and repeated stress relaxation tests at 293 K, 573 K, and 773 K. The minimum in the total elongation was indicative of dynamic strain aging phenomenon in this alloy in the intermediate temperature regime. The yield stress of the alloy was separated into effective and athermal components and the transition from thermally activated dislocation glide to athermal regime took place at around 673 K with the athermal stress estimated to be 115 MPa. The activation volume was found to be in the range of 40 b3 to 160 b3. The activation volume values and the data analyses using the solid-solution models in literature indicated dislocation-solute interaction to be a potential deformation mechanism in thermally activated regime. The activation energy calculated at 573 K was very close to that found for diffusivity of oxygen in α-Zr that was suggestive of dislocations-oxygen interaction during plastic deformation. This type of information may be helpful in alloy design in selecting different elements to control the deformation behavior of the material and impart desired mechanical properties in those materials for specific applications.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Kumar, N. and Alomari, A. and Murty, K. L.}, year={2018}, month={Jun}, pages={41–49} } @inbook{kumar_grundy_kombaiah_luan_murty_2017, title={Anisotropic Biaxial Creep of Textured Nb-Modified Zircaloy-4 Tubing}, ISBN={9783319510965 9783319510972}, ISSN={2367-1181 2367-1696}, url={http://dx.doi.org/10.1007/978-3-319-51097-2_2}, DOI={10.1007/978-3-319-51097-2_2}, abstractNote={Biaxial creep of Nb-modified Zircaloy-4 (HANA-4) tubing is investigated at varied ratios of hoop and axial stresses at a constant temperature of 500 °C using internal pressurization superimposed with axial load while monitoring the hoop and axial strains using non-contact laser telemetric extensometer and linear variable differential transducer, respectively. Steady-state creep rates along the hoop and axial directions were evaluated in the power-law creep regime from which the creep locus was derived at a constant energy of dissipation. The resulting creep locus was compared with that predicted by the anisotropy parameters, R and P in the Hill's formulation for generalized stress for anisotropic materials. Crystallographic texture of the tubing was characterized using electron backscatter diffraction technique. Research is supported by NSF grant #DMR0968825.}, booktitle={Mechanical and Creep Behavior of Advanced Materials}, publisher={Springer International Publishing}, author={Kumar, Nilesh and Grundy, Kaitlin and Kombaiah, Boopathy and Luan, Baifeng and Murty, Korukonda}, year={2017}, pages={19–32} } @inbook{murty_2017, title={Creep, Deformation and Fracture Studies of Materials for Various Technologies in the Nuclear Materials Research Group at NC State}, ISBN={9783319510965 9783319510972}, ISSN={2367-1181 2367-1696}, url={http://dx.doi.org/10.1007/978-3-319-51097-2_1}, DOI={10.1007/978-3-319-51097-2_1}, abstractNote={A brief outline of the research activities during the past three decades in the Nuclear Materials Research Group at NC State University is summarized that comprises of creep mechanisms in materials, reliability of solders in electronic packaging, dynamic strain aging, radiation embrittlement of ferritic steels, anisotropic biaxial creep of hexagonal closed packed metals with emphasis on Zircaloy cladding, in-service monitoring of structural materials using ABI, non-interactive Nuclear Magnetic Resonance studies of dynamical behavior of point and line defects during deformation, and radiation effects in nanocrystalline materials. All the described aspects are the outcomes of research experiences of the author starting from his MS thesis at Cornell University on creep of alpha iron and doctoral thesis research on NMR studies followed by post-doctoral research at the University of California in Berkeley on creep and superplasticity, and University of Newcastle, Australia on radiation effects on yield point phenomena in steels.}, booktitle={Mechanical and Creep Behavior of Advanced Materials}, publisher={Springer International Publishing}, author={Murty, Korukonda Linga}, year={2017}, pages={3–18} } @article{kombaiah_murty_2017, title={Dislocation Cross-Slip Controlled Creep at High Stresses and Transitional Creep Mechanisms in Zircaloy-4}, ISBN={["978-3-319-51096-5"]}, ISSN={["2367-1181"]}, DOI={10.1007/978-3-319-51097-2_6}, abstractNote={Uniaxial creep tests were performed on Zircaloy-4 sheet in the temperature range of 500–600 °C at high stresses (>10−3E, E is the elastic modulus) to uncover the rate-controlling mechanism. Stress exponents and stress-dependent activation energies, respectively, in the range of 9.3–11 and 220–242 kJ/mol were obtained from the steady state creep rate data. TEM analyses on the deformed specimens revealed extensive hexagonal screw dislocation networks on the basal planes indicating recovery of screw dislocations by cross-slip to be the dominant mechanism. Furthermore, analysis of the creep data in the light of Friedel’s cross slip model for HCP metals and the activation volume of the operating deformation mechanisms measured using stress relaxation tests favor cross-slip of screw dislocations as the rate controlling mechanism in the creep testing conditions employed in this study. In addition, transitions in creep mechanisms of Zircaloy-4 are presented along with its application to the evaluation of the total strain accumulated in Zircaloy-4 fuel cladding during dry storage.}, journal={MECHANICAL AND CREEP BEHAVIOR OF ADVANCED MATERIALS}, author={Kombaiah, B. and Murty, K. Linga}, year={2017}, pages={65–77} } @inbook{wang_luan_murty_liu_2017, title={Effect of Mo and Bi Additions on the Microstructure of Zr–Cr–Fe Alloy After β-Quenching}, ISBN={9783319510965 9783319510972}, ISSN={2367-1181 2367-1696}, url={http://dx.doi.org/10.1007/978-3-319-51097-2_14}, DOI={10.1007/978-3-319-51097-2_14}, abstractNote={This work investigated the solid-states phase transformation behavior of Zr–Cr–Fe alloys during rapid cooling from β-phase region. Scanning electron microscopy (SEM) was used to characterize the microstructure evolution of Zr–Cr–Fe alloys containing different Mo and Bi contents. The results show that two different phase transformation modes were involved during β to α transformation for different domains within prior β grains: (i) Martensitic transformation resulting in lath-shaped grains occured within prior β grain interiors. (ii) Massive transformation generating massive-shaped grains initiated along two adjacent prior β parent grain boundaries. Alpha (α) lath width reduced with increasing Mo concentration while Mo strongly retarded massive phase transformation. Interestingly microstructures exhibited no significant variation in the case of specimens containing different Bi contents irrespective of the phase transformation modes.}, booktitle={Mechanical and Creep Behavior of Advanced Materials}, publisher={Springer International Publishing}, author={Wang, Jianmin and Luan, Baifeng and Murty, Korukonda L. and Liu, Qing}, year={2017}, pages={183–192} } @article{qiu_song_luan_yue_wang_yuan_murty_liu_2017, title={Evolution of microstructure and second-phase particles in Zr-Sn-Nb-Fe alloy tube during Pilger processing}, volume={54}, ISSN={["1881-1248"]}, DOI={10.1080/00223131.2017.1365023}, abstractNote={ABSTRACT Evolution of microstructure and second-phase particles (SPPs) in Zr–Sn–Nb–Fe alloy tube were investigated during Pilger process using electron backscatter diffraction, secondary electron and transmission electron microscopy imaging techniques. Results show that the Pilger rolled tubes present heterogeneous structures with the C axes of less deformed grains mostly concentrated in the axial direction. During the Pilger rolling, the increase of deformation caused weakening of linear distribution of second-phase particles. The mean diameters of the precipitates are in the range of 70–100 nm in all specimens, and the growth mechanism of SPPs follows second-order kinetics. The grain growth is controlled by Zener pinning in the Pilger rolling–annealing specimens. Clusters containing the Zr(Nb,Fe)2 and βNb precipitates formed in the Zr–1.0Sn–1.0Nb–0.12Fe alloy. Most of the particles located in grain boundaries are the Zr(Nb,Fe)2 Laves phase with hexagonal structure, and stacking faults have been found in the Zr(Nb,Fe)2 precipitates. The types, morphology and distribution of precipitates depend on the constituent and structural fluctuations of the nucleation area.}, number={12}, journal={JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY}, author={Qiu, Risheng and Song, Zhenli and Luan, Baifeng and Yue, Qiang and Wang, Lian and Yuan, Gaihuan and Murty, Korukonda Linga and Liu, Qing}, year={2017}, pages={1321–1329} } @article{mohamed_gollapudi_charit_murty_2018, title={Formability of a wrought Mg alloy evaluated by impression testing}, volume={712}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2017.11.088}, abstractNote={This study is focused on furthering our understanding of the different factors that influence the formability of Magnesium alloys. Towards this end, formability studies were undertaken on a wrought Mg-2Zn-1Mn (ZM21) alloy. In contrast to conventional formability studies, the impression testing method was adopted here to evaluate the formability parameter, B, at temperatures ranging from 298 to 473 K. The variation of B of ZM21 with temperature and its rather limited values were discussed in the light of different deformation mechanisms such as activation of twinning, slip, grain boundary sliding (GBS) and dynamic recrystallization (DRX). It was found that the material characteristics such as grain size, texture and testing conditions such as temperature and strain rate, were key determinants of the mechanism of plastic deformation. A by-product of this analysis was the observation of an interesting correlation between the Zener-Hollomon parameter, Z, and the ability of Mg alloys to undergo DRX.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Mohamed, Walid and Gollapudi, Srikant and Charit, Indrajit and Murty, K. Linga}, year={2018}, month={Jan}, pages={140–145} } @inbook{roodposhti_murty_2017, title={Fracture Behavior and Grain Boundary Sliding During High-Temperature Low-Stress Deformation of AZ31 Magnesium Alloy}, ISBN={9783319510965 9783319510972}, ISSN={2367-1181 2367-1696}, url={http://dx.doi.org/10.1007/978-3-319-51097-2_23}, DOI={10.1007/978-3-319-51097-2_23}, abstractNote={Low-stress high-temperature tensile-creep behavior of AZ31 Mg alloy was investigated to characterize microstructure evolution, uncover dominant creep mechanism and find a correlation with common creep models. The stress exponent, inverse grain size exponent and activation energy value were evaluated. Cavity nucleation from stress concentration sites, types of fracture surfaces and microstructural evidence of grain migrations were observed in crept samples that are indicative of Rachinger mechanism of grain boundary sliding (GBS). Experimental data reveal a reasonable correlation with Langdon’s model. Further analysis on fracture behavior of this alloy in a wider range of stresses show that they follow Monkman-Grant model in predicting the fracture time.}, booktitle={Mechanical and Creep Behavior of Advanced Materials}, publisher={Springer International Publishing}, author={Roodposhti, Peiman Shahbeigi and Murty, Korukonda L.}, year={2017}, pages={279–287} } @inbook{kumar_alsabbagh_seok_murty_2017, title={Synergistic Effects of Neutron Irradiation and Interstitial Nitrogen on Strain Aging in Ferritic Steels}, ISBN={9783319510965 9783319510972}, ISSN={2367-1181 2367-1696}, url={http://dx.doi.org/10.1007/978-3-319-51097-2_12}, DOI={10.1007/978-3-319-51097-2_12}, abstractNote={Ferritic steels that are generally used in pressure vessels and various reactor support structures in light water reactors exhibit dynamic strain aging (DSA) resulting in increased work-hardening accompanied by ductility loss. While there is a possibility of adding this embrittlement known as blue brittleness to the well-known radiation embrittlement, it has been amply demonstrated that radiation exposure leads to decreased concentrations of interstitial impurity atoms in solution. Thus the critical temperature for DSA increases with increased neutron fluence very similar to the increase observed in dry hydrogen treated mild steel samples with decreased concentration of nitrogen in solution with increased treatment time. We summarize here the mechanical and fracture studies made on three different materials: a mild steel and two ferritic steels (A533B and A516 Grade70). In addition, effects of interstitial nitrogen are evaluated by heat treating to different times in dry hydrogen atmosphere.}, booktitle={Mechanical and Creep Behavior of Advanced Materials}, publisher={Springer International Publishing}, author={Kumar, N. and Alsabbagh, A. and Seok, C. S. and Murty, K. L.}, year={2017}, pages={151–164} } @article{kumar_fusco_komarasamy_mishra_bourham_murty_2017, title={Understanding effect of 3.5 wt.% NaCl on the corrosion of Al0.1CoCrFeNi high-entropy alloy}, volume={495}, ISSN={0022-3115}, url={http://dx.doi.org/10.1016/j.jnucmat.2017.08.015}, DOI={10.1016/j.jnucmat.2017.08.015}, abstractNote={High entropy alloys are a new class of metallic materials with potential for use in a wide variety of applications including their use in corrosive environment. The present study focused on the corrosion behavior of a single-phase, face-centered cubic high entropy alloy (HEA) Al0.1CoCrFeNi in as-cast condition, and the results are compared with the corrosion behavior of the SS304. The microstructural characterization of the alloys in as-received condition was carried out using optical microscopy, electron backscattered diffraction, energy dispersive spectroscopy, and X-ray diffraction. Corrosion behavior was studied using potentiodynamic polarization test in a 3.5 wt% NaCl solution and electrochemical impedance spectroscopy at room temperature. It was observed that the general corrosion resistance of the HEA was better than that of SS304. Pitting potential of the HEA was found to be superior to that of the SS304. Corrosion pits size was slightly smaller in SS304 than that in the HEA. 3D imaging determined that the pit depths were of the same order in both cases. Overall, the HEA Al0.1CoCrFeNi demonstrated a better resistance to general and pitting corrosion.}, journal={Journal of Nuclear Materials}, publisher={Elsevier BV}, author={Kumar, N. and Fusco, M. and Komarasamy, M. and Mishra, R.S. and Bourham, M. and Murty, K.L.}, year={2017}, month={Nov}, pages={154–163} } @inproceedings{kumar_alomari_murty_2017, title={Understanding plastic deformation mechanism(s) in recrystallized Zircaloy-4}, DOI={10.1115/msec2017-2882}, abstractNote={It is essential to understand basic deformation mechanism(s) of conventional alloys in order to develop improved or novel alloys for their applications in much more challenging conditions. Zircaloy-4 is extensively used in pressurized water reactor for nuclear fuel cladding application. It operates at very high temperature in the presence of mechanical loads, corrosive atmosphere, and neutron irradiation environment. Present work explores the fundamental plastic deformation mechanism(s) of Zircaloy-4 in the temperature range 20 to 600 °C by subjecting tensile samples to uniaxial tensile loads under quasi-static deformation conditions. Based on the results of uniaxial tensile testing as a function of temperature, repeated stress-relaxation experiments were carried out to determine the activation volume of the alloy at 20 and 500 °C. The results from uniaxial tensile and stress-relaxation testing were used to gain insight into potential deformation mechanism(s) in Zircaloy-4.}, booktitle={Proceedings of the ASME 12th International Manufacturing Science and Engineering Conference - 2017, vol 2}, author={Kumar, N. and Alomari, A. and Murty, K. L.}, year={2017} } @article{chai_wang_wu_guo_pan_chen_murty_song_2017, title={alpha ->beta Transformation characteristics revealed by pulsed laser-induced non-equilibrium microstructures in duplex-phase Zr alloy}, volume={60}, ISSN={["1869-1900"]}, DOI={10.1007/s11431-016-9038-y}, number={8}, journal={SCIENCE CHINA-TECHNOLOGICAL SCIENCES}, author={Chai, LinJiang and Wang, ShuYan and Wu, Hao and Guo, Ning and Pan, HuCheng and Chen, LiangYu and Murty, K. L. and Song, Bo}, year={2017}, month={Aug}, pages={1255–1262} } @article{shahbeigi roodposhti_sarkar_murty_scattergood_2016, title={Effects of Microstructure and Processing Methods on Creep Behavior of AZ91 Magnesium Alloy}, volume={25}, ISSN={1059-9495 1544-1024}, url={http://dx.doi.org/10.1007/S11665-016-2222-1}, DOI={10.1007/S11665-016-2222-1}, number={9}, journal={Journal of Materials Engineering and Performance}, publisher={Springer Science and Business Media LLC}, author={Shahbeigi Roodposhti, Peiman and Sarkar, Apu and Murty, Korukonda L. and Scattergood, Ronald O.}, year={2016}, month={Jul}, pages={3697–3709} } @article{roodposhti_sarkar_murty_brody_scattergood_2016, title={Grain boundary sliding mechanism during high temperature deformation of AZ31 Magnesium alloy}, volume={669}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2016.05.076}, abstractNote={High temperature tensile creep tests were conducted on AZ31 Magnesium alloy at low stress range of 1–13 MPa to clarify the existence of grain boundary sliding (GBS) mechanism during creep deformation. Experimental data within the GBS regime shows the stress exponent is ~2 and the activation energy value is close to that for grain boundary diffusion. Analyses of the fracture surface of the sample revealed that the GBS provides many stress concentrated sites for diffusional cavities formation and leads to premature failure. Scanning electron microscopy images show the appearances of both ductile and brittle type fracture mechanism. X-ray diffraction line profile analysis (based on Williamson-Hall technique) shows a reduction in dislocation density due to dynamic recovery (DRV). A correlation between experimental data and Langdon's model for GBS was also demonstrated.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Roodposhti, Peiman Shahbeigi and Sarkar, Apu and Murty, Korukonda Linga and Brody, Harold and Scattergood, Ronald}, year={2016}, month={Jul}, pages={171–177} } @article{chai_chen_wang_zhang_murty_2016, title={Microstructural, textural and hardness evolution of commercially pure Zr surface-treated by high current pulsed electron beam}, volume={390}, ISSN={["1873-5584"]}, DOI={10.1016/j.apsusc.2016.08.128}, abstractNote={High current pulsed electron beam (HCPEB) treatments were performed for a commercially pure Zr sheet, with remarkable surface modifications demonstrated. After the HCPEB treatments, the prior equiaxed grains with a bimodal basal texture are replaced by ultra fine plates with dense nanotwins and an unusual fiber texture of <112¯0> normal to the sheet surface. Increased number of pulses leads to further refined microstructures and intensified textures, jointly resulting in continuous increase of hardness. Reasons for such modifications could mainly be attributed to ultra fast heating/cooling and strong variant selection due to presence of complex thermal and stress fields.}, journal={APPLIED SURFACE SCIENCE}, author={Chai, Linjiang and Chen, Baofeng and Wang, Shuyan and Zhang, Zhuo and Murty, Korukonda L.}, year={2016}, month={Dec}, pages={430–434} } @article{sarkar_eapen_raj_murty_burchell_2016, title={Modeling irradiation creep of graphite using rate theory}, volume={473}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2016.01.036}, abstractNote={We have examined irradiation induced creep of graphite in the framework of transition state rate theory. Experimental data for two grades of nuclear graphite (H-337 and AGOT) have been analyzed to determine the stress exponent (n) and activation energy (Q) for plastic flow under irradiation. We show that the mean activation energy lies between 0.14 and 0.32 eV with a mean stress-exponent of 1.0 ± 0.2. A stress exponent of unity and the unusually low activation energies strongly indicate a diffusive defect transport mechanism for neutron doses in the range of 3–4 × 1022 n/cm2.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Sarkar, Apu and Eapen, Jacob and Raj, Anant and Murty, K. L. and Burchell, T. D.}, year={2016}, month={May}, pages={197–205} } @article{mohamed_miller_porter_murty_2016, title={The Role of Grain Size on Neutron Irradiation Response of Nanocrystalline Copper}, volume={9}, ISSN={["1996-1944"]}, DOI={10.3390/ma9030144}, abstractNote={The role of grain size on the developed microstructure and mechanical properties of neutron irradiated nanocrystalline copper was investigated by comparing the radiation response of material to the conventional micrograined counterpart. Nanocrystalline (nc) and micrograined (MG) copper samples were subjected to a range of neutron exposure levels from 0.0034 to 2 dpa. At all damage levels, the response of MG-copper was governed by radiation hardening manifested by an increase in strength with accompanying ductility loss. Conversely, the response of nc-copper to neutron irradiation exhibited a dependence on the damage level. At low damage levels, grain growth was the primary response, with radiation hardening and embrittlement becoming the dominant responses with increasing damage levels. Annealing experiments revealed that grain growth in nc-copper is composed of both thermally-activated and irradiation-induced components. Tensile tests revealed minimal change in the source hardening component of the yield stress in MG-copper, while the source hardening component was found to decrease with increasing radiation exposure in nc-copper.}, number={3}, journal={MATERIALS}, author={Mohamed, Walid and Miller, Brandon and Porter, Douglas and Murty, Korukonda}, year={2016}, month={Mar} } @article{zhang_luan_song_xin_murty_liu_2016, title={{112̅1}-{101̅2} double twinning in a Zircaloy-4 alloy during rolling at ambient temperature}, volume={122}, ISSN={1359-6462}, url={http://dx.doi.org/10.1016/J.SCRIPTAMAT.2016.05.003}, DOI={10.1016/J.SCRIPTAMAT.2016.05.003}, abstractNote={In this paper, we report the formation of an atypical double twinning sequence in Zircaloy-4 during rolling at room temperature. The grain orientation analysis based on electron backscattering diffraction (EBSD) data reveals that this double twinning mode is of the 112̅1-101̅2 type, namely, the secondary 101̅2 twin generated within the primary 112̅1 twin. Based on the combinative analysis of Schmid factor and local strain accommodation, the formation and variant selection mechanism of this double twinning are discussed.}, journal={Scripta Materialia}, publisher={Elsevier BV}, author={Zhang, M. and Luan, B.F. and Song, Z.L. and Xin, R.L. and Murty, K.L. and Liu, Q.}, year={2016}, month={Sep}, pages={77–81} } @article{chai_chen_zhou_murty_ma_huang_2015, title={A special twin relationship or a common Burgers misorientation between alpha plates after beta quenching in Zr alloy?}, volume={104}, ISSN={["1873-4189"]}, DOI={10.1016/j.matchar.2015.04.008}, abstractNote={A 101¯1 twin relationship between α plates was repeatedly reported in β-quenched Zr alloys in literature. In this paper, however, we demonstrate that the special twin relationship between α plates should be correctly identified as one of five common Burgers misorientations. The shared plane between two α plates with such a Burgers misorientation is determined to be 101¯1.06. Such a clarification helps to reach more accurate understanding of boundary characteristics of β-quenched microstructure in Zr alloys.}, journal={MATERIALS CHARACTERIZATION}, author={Chai, Linjiang and Chen, Baofeng and Zhou, Zhiming and Murty, Korukonda L. and Ma, Yanlong and Huang, Weijiu}, year={2015}, month={Jun}, pages={61–65} } @article{kombaiah_murty_2015, title={Coble, Orowan Strengthening, and Dislocation Climb Mechanisms in a Nb-Modified Zircaloy Cladding}, volume={46A}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-015-3060-8}, abstractNote={Biaxial creep tests on HANA-4 tubes, Nb-added Zircaloy-4 were conducted using internal pressurization of closed-end tubes to investigate the rate-controlling mechanisms over a range of hoop stresses, $$ 8.38 \times 10^{ - 5} E - 2.87 \times 10^{ - 3} E $$ , at three different temperatures 673 K, 723 K, and 773 K (400 °C, 450 °C, and 500 °C). The mechanistic creep parameters such as stress exponent (n) and activation energy (Q C) were then determined from steady-state creep rates. Based on the variance in stress exponent with respect to the applied stress, three regimes have been identified: a stress exponent close to 1 at low stresses that increased to 3 at the intermediate stresses, which became 4.5 at high stresses. An activation energy value of 226 kJ/mol was evaluated for the n = 3 and n = 4.5 regimes, which lies close to the activation energy for self-diffusion (Q L) in α-Zr alloys. Further, TEM analyses of crept microstructures and comparison of experimental results with standard models were undertaken to find out the rate-controlling mechanisms. Coble creep, climbing of dislocations to bypass β-Nb precipitates, and dynamic recovery by edge dislocation climb are proposed as the rate-controlling mechanisms in the n = 1, n = 3, and n = 4.5 regimes of HANA-4, respectively.}, number={10}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Kombaiah, Boopathy and Murty, Korukonda Linga}, year={2015}, month={Oct}, pages={4646–4660} } @article{roodposhti_sarkar_murty_scattergood_2015, title={Dislocation Density Evolution During Creep of AZ31 Mg Alloy: A Study by X-ray Diffraction Line Profile Analysis}, volume={4}, ISSN={2192-9262 2192-9270}, url={http://dx.doi.org/10.1007/S13632-015-0220-6}, DOI={10.1007/S13632-015-0220-6}, number={5}, journal={Metallography, Microstructure, and Analysis}, publisher={Springer Science and Business Media LLC}, author={Roodposhti, Peiman Shahbeigi and Sarkar, Apu and Murty, Korukonda L. and Scattergood, Ronald O.}, year={2015}, month={Sep}, pages={337–343} } @article{roodposhti_sarkar_murty_2015, title={Fracture Behavior of AZ31 Magnesium Alloy During Low-Stress High-Temperature Deformation}, volume={4}, ISSN={2192-9262 2192-9270}, url={http://dx.doi.org/10.1007/S13632-015-0189-1}, DOI={10.1007/S13632-015-0189-1}, number={2}, journal={Metallography, Microstructure, and Analysis}, publisher={Springer Science and Business Media LLC}, author={Roodposhti, Peiman Shahbeigi and Sarkar, Apu and Murty, Korukonda Linga}, year={2015}, month={Feb}, pages={91–101} } @article{kombaiah_murty_2015, title={High temperature creep and deformation microstructures in recrystallized Zircaloy-4}, volume={95}, ISSN={["1478-6443"]}, DOI={10.1080/14786435.2015.1042939}, abstractNote={Uniaxial creep tests were performed on recrystallized Zircaloy-4 tensile specimens with an average grain size of 8.5 μm at the stress range of , where E is the elastic modulus, at three temperatures: 500, 550 and 600 °C with an objective to uncover the rate-controlling mechanism(s). A transition in creep mechanism was observed as the stress exponent increased from a value close to 1 at the low stress range to 4.1 at high stresses with the calculated activation energies (Qc) of 196 kJ/mol and 241 kJ/mol, respectively. Possible creep mechanisms have been shortlisted based upon the values of n and Qc. Transmission electron microscopy analyses of the dislocation structures in the crept specimens as well as validation of the experimental results with the predictions by standard creep models were undertaken to ascertain the underlying rate-controlling mechanisms. While Coble creep was noted to be the dominant mechanism in the n ~ 1 regime at low stresses, dislocation climb was identified to control the creep rate in the n ~ 4.1 regime at high stresses.}, number={15}, journal={PHILOSOPHICAL MAGAZINE}, author={Kombaiah, B. and Murty, K. Linga}, year={2015}, month={May}, pages={1656–1679} } @article{sarkar_maloy_murty_2015, title={Investigation of Portevin - Le Chatelier effect in HT-9 steel}, volume={631}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2015.02.022}, abstractNote={Portevin−Le Chatelier (PLC) effect has been observed in HT-9 steel. The present study involves different types of tensile testing to characterize the features of PLC effectin HT-9 steel. Stress serrations observed during tensile tests are analyzed using different statistical analysis techniques to investigate the underlying nature of the effect. Peaked type of stress drop distribution indicated occurrence of type B serrations in the steel. Multiscale entropy analysis of the stress serrations indicated substitutional solute atoms to be responsible for the PLC effect in HT-9 steel.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Sarkar, Apu and Maloy, Sturat A. and Murty, Korukonda L.}, year={2015}, month={Apr}, pages={120–125} } @article{chai_luan_xiao_zhang_murty_liu_2015, title={Microstructural and textural evolution of commercially pure Zr sheet rolled at room and liquid nitrogen temperatures}, volume={85}, ISSN={["1873-4197"]}, DOI={10.1016/j.matdes.2015.06.088}, abstractNote={A commercially pure Zr sheet with a typical bimodal basal texture was rolled up to 70% reductions at room temperature (RT) and liquid nitrogen temperature (LNT) to follow its microstructural and textural evolution. Various features developed during rolling were interpreted largely based on analyses on active deformation modes by the use of electron backscatter diffraction (EBSD) technique. Results show that only dislocation slip is activated during RT rolling while both slip and twinning occur in LNT-rolled specimens. There are always some non-deforming grains after RT rolling because their orientations with the c-axes close to the normal direction (ND) of the Zr sheet are unfavorable for slip. The LNT rolling allows these non-deforming grains to be deformed by 112¯2<11¯23> compressive twinning and thus leads to more homogenous microstructures. The angle between basal pole peaks and the ND slightly decreases during RT rolling, which is attributed to the activity of 101¯1<112¯3> pyramidal slip. Many twins initiated at the early stage of LNT rolling could help retard the centralization of bimodal basal texture. In addition, calculations in light of key structural parameters measured by the EBSD reveal that the contribution from grain refinement induced by twinning makes the LNT-rolled specimens harder than the RT-rolled specimens.}, journal={MATERIALS & DESIGN}, author={Chai, Linjiang and Luan, Baifeng and Xiao, Dongping and Zhang, Min and Murty, Korukonda L. and Liu, Qing}, year={2015}, month={Nov}, pages={296–308} } @article{roodposhti_farahbakhsh_sarkar_murty_2015, title={Microstructural approach to equal channel angular processing of commercially pure titanium—A review}, volume={25}, ISSN={1003-6326}, url={http://dx.doi.org/10.1016/S1003-6326(15)63734-7}, DOI={10.1016/S1003-6326(15)63734-7}, abstractNote={A review on severe plastic deformation (SPD) technique of equal channel angular pressing (ECAP) process of commercially pure titanium (CP-Ti) alloys was presented with a major emphasize on the influence of ECAP parameters that include channel and curvature angles, processing route, temperature of operation, pressing speed, internal heating, number of pass through the die and back pressure. Various ECAP characteristics such as microstructure, strain inhomogeneity and mechanical properties are considered to achieve the maximum homogeneity, equilibrium grain refinement and mechanical improvement of CP-Ti. Investigations show that a pressing speed of 1–3 mm/s at 450 °C with route BC along with channel and curvature angles of 90°and 20° respectively with backpressure can lead to the most homogeneous ultrafine microstructure.}, number={5}, journal={Transactions of Nonferrous Metals Society of China}, publisher={Elsevier BV}, author={Roodposhti, Peiman Shahbeigi and Farahbakhsh, Nasim and Sarkar, Apu and Murty, Korukonda Linga}, year={2015}, month={May}, pages={1353–1366} } @article{sarkar_boopathy_eapen_murty_2014, title={Creep Behavior of Hydrogenated Zirconium Alloys}, volume={23}, ISSN={["1544-1024"]}, DOI={10.1007/s11665-014-1129-y}, number={10}, journal={JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE}, author={Sarkar, A. and Boopathy, K. and Eapen, J. and Murty, K. L.}, year={2014}, month={Oct}, pages={3649–3656} } @article{kombaiah_murty_2015, title={Dislocation cross-slip controlled creep in Zircaloy-4 at high stresses}, volume={623}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2014.11.040}, abstractNote={Uniaxial creep tests were performed on Zircaloy-4 sheet in the temperature range of 500–600 °C at high stresses (>10−3E), to uncover the rate-controlling mechanism. A stress exponent of 9.3–11 and a stress-dependent activation energy in the range of 220–242 kJ/mol were obtained from the steady state creep data. TEM analyses revealed an extensive presence of hexagonal screw dislocation network on the basal planes indicating recovery of screw dislocations by cross-slip to be the dominant mechanism. The creep data was therefore analyzed in the light of Friedel׳s cross slip model for HCP metals according to which the stress-dependency of the activation energy determined from the creep data was written in the form,U=(150±4)+(2236±124τ)kJ/mol The constriction energy of screw dislocations of 150 kJ/mol is in agreement with the values reported in the literature for zirconium and other HCP metals. Further analysis of the yield strength and the activation volume data obtained from stress relaxation tests in the temperature range 500–600 °C favors cross-slip of screw dislocations as the rate controlling mechanism over the test conditions.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Kombaiah, B. and Murty, K. Linga}, year={2015}, month={Jan}, pages={114–123} } @inbook{sarkar_alsabbagh_murty_2014, title={Effect of Low Dose Neutron Irradiation on Tensile Behavior of HT-9 Steel at Room Temperature}, ISBN={9783319485935 9783319482378}, url={http://dx.doi.org/10.1007/978-3-319-48237-8_20}, DOI={10.1007/978-3-319-48237-8_20}, booktitle={TMS 2014: 143rd Annual Meeting & Exhibition}, publisher={Springer International Publishing}, author={Sarkar, A. and Alsabbagh, A. H. and Murty, K. L.}, year={2014}, pages={147–154} } @article{varam_rajulapati_rao_scattergood_murty_koch_2014, title={Loading Rate-Dependent Mechanical Properties of Bulk Two-Phase Nanocrystalline Al-Pb Alloys Studied by Nanoindentation}, volume={45A}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-014-2425-8}, number={11}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Varam, Sreedevi and Rajulapati, Koteswararao V. and Rao, K. Bhanu Sankara and Scattergood, Ronald O. and Murty, Korukonda L. and Koch, Carl C.}, year={2014}, month={Oct}, pages={5249–5258} } @article{roodposhti_sarkar_murty_2015, title={Microstructural development of high temperature deformed AZ31 magnesium alloys}, volume={626}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2014.12.064}, abstractNote={Due to their significant role in automobile industries, high temperature deformation of Mg–Al–Zn alloys (AZ31) at constant stress (i.e. creep) were studied at a wide range of stresses and temperatures to characterize underlying deformation mechanism, dynamic recrystallization (DRX) and dislocation density evolution. Various microstructures (e.g. grain growth & DRX) are noted during steady-state creep mechanisms such as grain boundary sliding (GBS), dislocation glide creep (DGC) and dislocation climb creep (DCC). Although a combination of DRX and grain growth is characteristic of low stacking fault energy materials like Mg alloys at elevated temperatures, observation reveals grain growth at low strain-rates (GBS region) along with dynamic recovery (DRV) mechanism. X-Ray Diffraction (XRD) analysis revealed a decrease in dislocation density during GBS region while it increased under dislocation based creep mechanisms which could be related to the possible DRV and DRX respectively. Scanning Electron Microscopic (SEM) characterization of the fracture surface reveals more inter-granular fracture for large grains (i.e. GBS region with DRV process) and more dimple shape fracture for small grains (i.e. DGC & DCC region with DRX).}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Roodposhti, Peiman Shahbeigi and Sarkar, Apu and Murty, Korukonda Linga}, year={2015}, month={Feb}, pages={195–202} } @article{alsabbagh_sarkar_miller_burns_squires_porter_cole_murty_2014, title={Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel}, volume={615}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2014.07.070}, abstractNote={Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) have been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.37 dpa. Atom probe tomography revealed manganese and silicon-enriched clusters in both UFG and CG steel after neutron irradiation. Mechanical properties were characterized using microhardness and tensile tests, and irradiation of UFG carbon steel revealed minute radiation effects in contrast to the distinct radiation hardening and reduction of ductility in its CG counterpart. After irradiation, micro hardness indicated increases of around 9% for UFG versus 62% for CG steel. Similarly, tensile strength revealed increases of 8% and 94% respectively for UFG and CG steels while corresponding decreases in ductility were 56% versus 82%. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation while no significant change was observed in UFG steel, revealing better radiation tolerance. Quantitative correlations between experimental results and modeling were demonstrated based on irradiation induced precipitate strengthening and dislocation forest hardening mechanisms.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Alsabbagh, Ahmad and Sarkar, Apu and Miller, Brandon and Burns, Jatuporn and Squires, Leah and Porter, Douglas and Cole, James I. and Murty, K. L.}, year={2014}, month={Oct}, pages={128–138} } @article{sarkar_murty_2015, title={Microstructure-mechanical property correlation of cryo rolled Zircaloy-4}, volume={456}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2014.09.071}, abstractNote={The evolution of microstructure and the mechanical properties of cryo-rolled Zircaloy-4 were both investigated to understand the origin of the alloy's strength processed at a cryogenic temperature. The correlation of dislocation density, grain size and yield stress of the rolled product indicated that an increase in dislocation density due to the suppression of dynamic recovery is the primary source of strengthening.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Sarkar, Apu and Murty, Korukonda L.}, year={2015}, month={Jan}, pages={287–291} } @article{murty_seok_kombaiah_2013, title={Burst and Biaxial Creep of Thin-Walled Tubing of Low c/a-Ratio HCP Metals}, volume={55}, ISSN={["1877-7058"]}, DOI={10.1016/j.proeng.2013.03.278}, abstractNote={Thin-walled tubing used in various structures are made of low c/a-ratio hcp metals such as Zr and Ti based alloys, and their integrity to internal pressures is of prime importance in the life of these engineering structures. We summarize here ome of the work performed on Zircaloy cladding commonly used in LWRs as thin walled tubing as well as Cp-Ti and Ti3Al2.5 V that find applications in aerospace industry. Considered here are three different types of tests: (i) burst tests using closed- end internal pressurization, (ii) uniaxial ring tests for characterization of hoop creep properties and (iii) hoop creep under biaxial internal pressurization. Burst and ring tests yielded identical hoop creep and rupture characteristics indicating the utility of ring tests to replace burst tests. Importance of transitions in creep mechanisms with decreased stress levels in predicting in-service dimensional changes is emphasized.}, journal={6TH INTERNATIONAL CONFERENCE ON CREEP, FATIGUE AND CREEP-FATIGUE INTERACTION}, author={Murty, K. Linga and Seok, C. S. and Kombaiah, B.}, year={2013}, pages={443–450} } @inproceedings{luan_qiu_zhou_murty_zhou_liu_2014, title={Characterization of hot deformation behavior of Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr using processing map}, DOI={10.1115/icone21-15186}, abstractNote={Hot deformation characteristics of forged and β-quenched Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr (N18 alloy) in the temperature range 625–950°C and in the strain rate range 0.005–5 s−1 have been studied by uniaxial compression testing of Gleeble 3500. For this study, the approach of processing maps has been adopted and their interpretation done using the Dynamic Materials Model (DMM). Based on a series of true stress-true strain curves on various temperatures and strain rates, the flow stress has been summarized and both the strain rate sensitivity index (m) and deformation activation energy (Q) have been calculated by the constitutive equations that flow stress and the relationship of Z parameter and flow stress have been established subsequently. Furthermore, the efficiency of power dissipation (⬜) given by [2m/(m+1)] and improved by Murty has been plotted as a function of temperature and strain rate to obtain different processing maps at different true strain rates ranging from 0.1–0.7. Subsequently, the microstructures of the specimens after compression testing were characterized by electron channeling contrast (ECC) imaging techniques used an FEI Nova 400 field emission gun scanning electron microscopy (FEG-SEM). The results showed that: (i) The hyperbolic sine constitutive equation can describe the flow stress behavior of zirconium alloy, and the deformation activation energy and flow stress equation were calculated under the different temperature stages which insists that the deformation mechanism is not dynamic recovery. (ii) The hot processing maps and its validation were analyzed, which indicated that the DMM theory was reliable and could be adopted as useful tool for optimizing hot workability of Zr. The optimum parameters for extrusion and hammer forging were revealed on the processing maps of 830–950°C, 0.048–2.141 s−1 and 916–950°C, 2.465–5 s−1. (iii) The microstructure of the ingot exhibits a typical lamellar Widmanstatten structure. Under the different strain rates, the grains formed by dynamic recrystallization existed normally in the central zone of the compression samples while the no uniformity of grain size increased with the increasing of strain rate. Meanwhile, due to the dynamic recrystallization as a thermal activation process, the grains size and uniformity increased with the increasing of temperature. In brief, microstructure analysis showed that continuous dynamic recrystallization and geometric dynamic recrystallization operated concurrently during the isothermal compressive deformation.}, booktitle={Proceedings of the 21st International Conference on Nuclear Engineering - 2013, vol 1}, author={Luan, B. F. and Qiu, R. S. and Zhou, Z. and Murty, K. L. and Zhou, J. and Liu, Q.}, year={2014} } @article{shrestha_gollapudi_charit_murty_2014, title={Creep deformation behavior of Sn-Zn solder alloys}, volume={49}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-013-7905-5}, number={5}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Shrestha, Triratna and Gollapudi, Srikant and Charit, Indrajit and Murty, K. Linga}, year={2014}, month={Mar}, pages={2127–2135} } @article{eapen_krishna_burchell_murty_2013, title={Early Damage Mechanisms in Nuclear Grade Graphite under Irradiation}, volume={2}, ISSN={2166-3831}, url={http://dx.doi.org/10.1080/21663831.2013.841782}, DOI={10.1080/21663831.2013.841782}, abstractNote={Using Raman and X-ray photoelectron spectroscopy, we delineate the bond and defect structures in nuclear block graphite (NBG-18) under neutron and ion irradiation. The strengthening of the defect (D) peak in the Raman spectra under irradiation is attributed to an increase in the topological, sp2-hybridized defects. Using transmission electron microscopy, we provide evidence for prismatic dislocations as well as a number of basal dislocations dissociating into Shockley partials. The non-vanishing D peak in the Raman spectra, together with a generous number of dislocations, even at low irradiation doses, indicates a dislocation-mediated amorphization process in graphite.}, number={1}, journal={Materials Research Letters}, publisher={Informa UK Limited}, author={Eapen, J. and Krishna, R. and Burchell, T. D. and Murty, K. L.}, year={2013}, month={Nov}, pages={43–50} } @inproceedings{luan_yang_wei_murty_long_liu_2014, title={Effect of Mo and Bi on mechanical properties of Zr-Fe-Cr alloy at room ternperature}, DOI={10.1115/icone21-15325}, abstractNote={To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.}, booktitle={Proceedings of the 21st International Conference on Nuclear Engineering - 2013, vol 1}, author={Luan, B. F. and Yang, L. Q. and Wei, T. G. and Murty, K. L. and Long, C. S. and Liu, Q.}, year={2014} } @article{chai_luan_murty_liu_2013, title={Effect of predeformation on microstructural evolution of a Zr alloy during 550-700 degrees C aging after beta quenching}, volume={61}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2013.02.001}, abstractNote={In this paper, we report the effect of a 20% predeformation on the microstructural evolution of a Zr–0.85Sn–0.4Nb–0.4Fe–0.1Cr–0.05Cu alloy during aging between 550 and 700 °C after β quenching. Transmission electron microscopy, electron backscatter diffraction, electron channeling contrast and secondary electron imaging techniques are jointly utilized to carry out detailed microstructural characterization. By comparing microstructures between directly aged specimens (group A) and specimens aged after a 20% predeformation (group B), it is revealed that the introduced predeformation could exert remarkable influences on the Zr alloy. As the aging temperature and/or time increase, initial plate structures finally recrystallize in both groups. In spite of the similarity of the general evolution profile, the predeformation introduced in group B evidently reduces the required aging temperature and time. Distinct recrystallization nucleation behaviors due to different recrystallization mechanisms are also found in both groups. Noticeable differences between the with- and without-predeformation groups also include grain size, distribution of second-phase particles and misorientation angle distribution features in recrystallized specimens. Reasons accounting for the accelerated recrystallization and distinct microstructural characteristics in group B are discussed and attributed to the defects introduced during the predeformation. In addition, grain size calculation by applying the Zener equation shows that, although equilibrium states are not attained in both groups, the case with the predeformation is closer to the ideal equilibrium.}, number={8}, journal={ACTA MATERIALIA}, author={Chai, Linjiang and Luan, Baifeng and Murty, Korukonda L. and Liu, Qing}, year={2013}, month={May}, pages={3099–3109} } @article{chai_luan_zhang_murty_liu_2013, title={Experimental observation of 12 alpha variants inherited from one beta grain in a Zr alloy}, volume={440}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2013.05.053}, abstractNote={Local crystallographic orientation characteristics of a Zr alloy after β cooling are investigated by electron backscatter diffraction (EBSD) technique. All misorientation peaks and corresponding rotation axes predicted by Burgers relationship are exclusively verified for the obtained basket-weave structure. Furthermore, by correlating microstructures and crystallographic orientations, all 12 possible α variants inherited from one prior β grain are definitely revealed. It is believed that excessive β grain growth in the Zr alloy is responsible for the weak or absence of variant selection during β cooling.}, number={1-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Chai, Linjiang and Luan, Baifeng and Zhang, Min and Murty, Korukonda L. and Liu, Qing}, year={2013}, month={Sep}, pages={377–381} } @article{alsabbagh_valiev_murty_2013, title={Influence of grain size on radiation effects in a low carbon steel}, volume={443}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2013.07.049}, abstractNote={Ultra-fine grain (UFG) metals with a relatively large volume of interfaces are expected to be more radiation resistant than conventional metals; grain boundaries act as unsaturable sinks for neutron irradiation induced defects. Effects of neutron irradiation on conventional and ultra-fine grain structured carbon steel are studied using the PULSTAR reactor at NC State University to relatively low fluence (∼1.15 × 10−3 dpa). The low dose irradiation of ultrafine grained carbon steel revealed minute radiation effects in contrast to the observed radiation hardening and reduction of ductility in its conventional grained counterpart.}, number={1-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Alsabbagh, Ahmad and Valiev, Ruslan Z. and Murty, K. L.}, year={2013}, month={Nov}, pages={302–310} } @article{sarkar_alsabbagh_murty_2014, title={Investigation of microstructure and mechanical properties of low dose neutron irradiated HT-9 steel}, volume={65}, ISSN={["0306-4549"]}, DOI={10.1016/j.anucene.2013.11.008}, abstractNote={HT-9 steel samples have been irradiated with fast neutrons (E > 0.1 MeV) to a low dose (1.2 × 10−3 dpa). Microstructure of the unirradiated and irradiated samples has been characterized by X-ray diffraction line profile analysis using different model-based approaches. The domain size and density of dislocations of the irradiated steel have been estimated. Different types of tensile tests have been carried out at room temperature to assess the changes in mechanical properties of HT-9 steel due to neutron irradiation.}, journal={ANNALS OF NUCLEAR ENERGY}, author={Sarkar, A. and Alsabbagh, A. H. and Murty, K. L.}, year={2014}, month={Mar}, pages={91–96} } @article{chai_luan_murty_liu_2013, title={Twinning during recrystallization cooling in alpha-Zr alloy}, volume={576}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2013.04.010}, abstractNote={Recently, twinning induced by intergranular thermal residual stresses (ITRSs) has been first reported in a Zr alloy after β→α furnace cooling. To further explore this kind of twinning behavior, microstructures and textures of the Zr alloy during α annealing between 650 and 750 °C after β quenching were investigated in the present work, by use of X-ray diffraction, electron backscatter diffraction and electron channeling contrast imaging techniques. Results indicate that the ITRS-induced twins could also occur during cooling after α-recrystallization annealing in the Zr alloy, closely related to both the grain size and the texture. When the recrystallization texture is relatively random, high tensile ITRSs up to ~200 MPa along c-axis could be accumulated. Tensile twins can only be induced by the tensile ITRS in the nearly texture-free Zr specimen with an average grain size larger than ~20 μm.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Chai, Linjiang and Luan, Baifeng and Murty, Korukonda L. and Liu, Qing}, year={2013}, month={Aug}, pages={320–325} } @article{gobien_murty_scattergood_goodwin_koch_2010, title={Creep behavior of ultra-fine grained Zn-4.5Al}, volume={527}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2010.08.020}, abstractNote={Creep tests were performed at 295 and 373 K on a cryogenically ball-milled Zn–4.5Al alloy. Creep tests on the as-milled microstructure having an average grain size of 260 nm showed clear signs of a threshold stress. The same material after a targeted heat treatment showed no signs of a threshold stress for the same alloy with an average grain size of 510 nm. In both cases stress exponent (n) values close to 1 and activation energies close to that of grain boundary diffusion were noted. Potential causes of the threshold stress are proposed as being a nanocrystalline oxide dispersion or non-uniform solute segregation, each of which could potentially interfere with grain boundary vacancy transfer mechanisms.}, number={27-28}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Gobien, J. M. and Murty, K. L. and Scattergood, R. O. and Goodwin, F. and Koch, C. C.}, year={2010}, month={Oct}, pages={7382–7386} } @article{gollapudi_rajulapati_charit_koch_scattergood_murty_2010, title={Creep in nanocrystalline materials: Role of stress assisted grain growth}, volume={527}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2010.05.048}, abstractNote={To date, only a limited number of creep studies have been carried out on nanocrystalline materials. These studies have remained largely inconclusive in establishing the creep mechanisms in nanocrystalline materials. The stress exponent and activation energy values obtained for nanocrystalline materials do not correlate well with conventional, well established creep models. Furthermore, discrepancy between experimentally determined deformation rates and theoretical predictions suggests that an entirely new mechanism of creep may be operational in these materials. Thus, this work aims to develop an understanding of the creep behavior of nanocrystalline materials by considering a stress assisted grain growth mechanism that has been recently identified in these materials. A model that provides an understanding of some observations made in creep literature has been developed. Impression creep data obtained from tests on nanocrystalline aluminum agree with model predictions.}, number={21-22}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Gollapudi, S. and Rajulapati, K. V. and Charit, I. and Koch, C. C. and Scattergood, R. O. and Murty, K. L.}, year={2010}, month={Aug}, pages={5773–5781} } @article{seok_marple_song_gollapudi_charit_murty_2011, title={High temperature deformation characteristics of Zirlo (TM) tubing via ring-creep and burst tests}, volume={241}, ISSN={["0029-5493"]}, DOI={10.1016/j.nucengdes.2010.04.017}, abstractNote={Abstract Fuel cladding tubing acting as a barrier between coolant and radioactive fuel pellets in light water reactors undergo a combination of mechanical and thermal effects along with corrosive conditions during normal operations as well as accident situations, such as LOCA, etc. Therefore, the mechanical integrity of the cladding tubing is of critical importance. In this study, high temperature deformation characteristics of niobium-containing zirconium alloy cladding materials (Zirlo™) have been evaluated via both ring-creep and burst tests. Creep-rupture data are presented in terms of Larson–Miller parameters (LMP). Data (creep rate vs. stress) from ring-creep and burst tests are analyzed, and operating deformation mechanisms are elucidated. This study demonstrates that the hoop creep data obtained from ring-creep and burst tests are equivalent, and one can be replaced with the other, if needed, in order to evaluate creep life.}, number={3}, journal={NUCLEAR ENGINEERING AND DESIGN}, author={Seok, C. S. and Marple, B. and Song, Y. J. and Gollapudi, S. and Charit, I. and Murty, K. L.}, year={2011}, month={Mar}, pages={599–602} } @article{burchell_murty_eapen_2010, title={Irradiation Induced Creep of Graphite}, volume={62}, ISSN={["1543-1851"]}, DOI={10.1007/s11837-010-0145-0}, number={9}, journal={JOM}, author={Burchell, T. D. and Murty, K. L. and Eapen, J.}, year={2010}, month={Sep}, pages={93–99} } @article{murty_2010, title={Materials for next-generation nuclear plants: Objectives and challenges}, volume={62}, DOI={10.1007/s11837-010-0139-y}, number={9}, journal={JOM: the Journal of the Minerals, Metals & Materials Society}, author={Murty, K. L.}, year={2010}, pages={60–61} } @article{murty_gollapudi_charit_2010, title={Newtonian viscous creep in metals}, volume={63}, ISSN={["0975-1645"]}, DOI={10.1007/s12666-010-0012-2}, number={2-3}, journal={TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS}, author={Murty, K. Linga and Gollapudi, S. and Charit, I.}, year={2010}, month={Apr}, pages={85–91} } @article{chant_murty_2010, title={Structural materials issues for the next generation fission reactors}, volume={62}, ISSN={1047-4838 1543-1851}, url={http://dx.doi.org/10.1007/S11837-010-0142-3}, DOI={10.1007/S11837-010-0142-3}, number={9}, journal={JOM}, publisher={Springer Science and Business Media LLC}, author={Chant, I. and Murty, K. L.}, year={2010}, month={Sep}, pages={67–74} } @article{chatterjee_murty_gayathri_mukherjee_barat_2011, title={Temperature Dependence of the Dynamics of Portevin-Le Chatelier Effect in Al-2.5 Pct Mg Alloy}, volume={42A}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-010-0530-x}, abstractNote={Tensile tests were carried out by deforming polycrystalline samples of Al-2.5 pct Mg alloy at four different temperatures in an intermediate strain rate regime of 2 × 10−4 s−1 to 2 × 10−3 s−1. The Portevin-Le Chatelier (PLC) effect was observed throughout the strain rate and temperature region. The mean cumulative stress drop magnitude and the mean reloading time exhibit an increasing trend with temperature, which is attributed to the enhanced solute diffusion at higher temperature. The observed stress–time series data were analyzed using the nonlinear dynamical methods. From the analyses, we established the presence of deterministic chaos in the PLC effect throughout the temperature regime. The dynamics goes to higher dimension at a sufficiently high temperature of 425 K (152 °C), but the complexity of the dynamics is not affected by the temperature.}, number={5}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Chatterjee, A. and Murty, K. L. and Gayathri, N. and Mukherjee, P. and Barat, P.}, year={2011}, month={May}, pages={1184–1190} } @article{gollapudi_rajulapati_charit_youssef_koch_scattergood_murty_2010, title={Understanding creep in nanocrystalline materials}, volume={63}, ISSN={["0975-1645"]}, DOI={10.1007/s12666-010-0050-9}, number={2-3}, journal={TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS}, author={Gollapudi, S. and Rajulapati, K. V. and Charit, I. and Youssef, K. M. and Koch, C. C. and Scattergood, R. O. and Murty, K. L.}, year={2010}, month={Apr}, pages={373–378} } @article{gollapudi_charit_murty_2008, title={Creep mechanisms in TI-3Al-2.5V alloy tubing deformed under closed-end internal gas pressurization}, volume={56}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2008.01.052}, abstractNote={Creep tests were carried out on Ti–3Al–2.5V alloy tubing in the temperature range of 723–873 K under closed-end internal pressurization. The data thus obtained were analyzed to obtain the mechanistic creep parameters (stress exponent and activation energy). Transitions in creep mechanisms were noted as the stress exponent varied from a lower value of 1 through 2 to a higher value of 5 with increasing stress where the activation energy assumed values of 232 and 325 kJ mol−1, respectively. The creep mechanisms were elucidated in the light of standard creep models supported by the substructures studied by transmission electron microscopy. Newtonian viscous creep (n = 1) at lower stresses was identified to be in accordance with a slip band model named after Spingarn and Nix. Grain boundary sliding with n = 2 was noted in an intermediate stress region while climb of edge dislocations was observed to control creep at higher stresses. Microstructural observations along with parametric variations of creep rates were useful in identifying the underlying deformation mechanisms.}, number={10}, journal={ACTA MATERIALIA}, author={Gollapudi, S. and Charit, I. and Murty, K. L.}, year={2008}, month={Jun}, pages={2406–2419} } @article{rajulapati_scattergood_murty_horita_langdon_koch_2008, title={Mechanical properties of bulk nanocrystalline aluminum-tungsten alloys}, volume={39A}, ISSN={["1073-5623"]}, DOI={10.1007/s11661-008-9593-3}, number={10}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Rajulapati, K. V. and Scattergood, R. O. and Murty, K. L. and Horita, Z. and Langdon, T. G. and Koch, C. C.}, year={2008}, month={Oct}, pages={2528–2534} } @article{gollapudi_bhosle_charit_murty_2008, title={Newtonian viscous creep in Ti-3Al-2.5V}, volume={88}, ISSN={["1478-6435"]}, DOI={10.1080/14786430802144154}, abstractNote={Biaxial creep tests were performed on fine-grained Ti–3Al–2.5V tubing at 823 and 873 K in the stress range σ/E  = 1.7  × 10−4 to σ/E  = 5.9  × 10−4. Subsequently, the creep data were analysed to determine the stress exponent and activation energy. A stress exponent value of 1 and an activation energy equal to that for grain boundary diffusion were suggestive of a Coble creep-controlled deformation regime. However, discrepancy between the experimental creep rates and Coble creep model predictions along with subsequent observation of deformed microstructures decorated with slip bands implied the operation of a different viscous creep mechanism. A slip band model proposed by Spingarn and Nix was found to provide a better description of the experimental strain rates rather than the conventional viscous creep mechanisms. High-resolution transmission electron microscopy studies confirmed the nature of these bands.}, number={9}, journal={PHILOSOPHICAL MAGAZINE}, author={Gollapudi, Srikant and Bhosle, Vikram and Charit, Indrajit and Murty, K. Linga}, year={2008}, pages={1357–1367} } @article{murty_charit_2008, title={Static strain aging and dislocation-impurity interactions in irradiated mild steel}, volume={382}, ISSN={["0022-3115"]}, DOI={10.1016/j.jnucmat.2008.08.008}, abstractNote={Interactions between dislocations and interstitial impurity atoms lead to strain aging phenomenon in ferritic steels that are affected by the defects produced during neutron radiation exposure. We present here results on static strain aging in a silicon-killed mild steel before and after neutron irradiation. It is noted that the degree of strain aging (as measured by the yield point following restraining) decreased with increasing neutron dose resulting in essentially non-aging type at the highest dose (∼1019 n/cm2). The strain aging kinetics were investigated using data at various aging temperatures and were found to be unaffected by the neutron radiation exposure. These experimental results are compared to those observed in dry hydrogen treated (partially denitrided) samples and are correlated with models on Cottrell locking.}, number={2-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Murty, K. L. and Charit, I.}, year={2008}, month={Dec}, pages={217–222} } @article{scattergood_koch_murty_brenner_2008, title={Strengthening mechanisms in nanocrystalline alloys}, volume={493}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2007.04.132}, abstractNote={The mechanisms for strengthening nanocrystalline metals by alloy additions are reviewed and a new model for nano-particle strengthening by Orowan bypassing in nano-grains is proposed. Recent experimental results for three different nanocrystalline alloy systems, Fe–Pb, Fe–Al2O3 and Al–Pb are presented and analyzed in terms of non-equilibrium solid solution strengthening, nano-composite strengthening and Orowan particle strengthening, respectively. Conflicting alloy hardening and softening effects observed in Al–Pb appear to be the result of interplay between Orowan particle hardening and a softening mechanism due to grain-boundary segregation. Preliminary MD simulations support the latter suggestion.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Scattergood, R. O. and Koch, C. C. and Murty, K. L. and Brenner, D.}, year={2008}, month={Oct}, pages={3–11} } @inproceedings{marple_song_gollapudi_murty_charit_2008, title={Stress rupture characteristics of zirconium alloy cladding under closed-end internal pressurization}, ISBN={9780791848142}, DOI={10.1115/icone16-48006}, abstractNote={An understanding of stress rupture behavior of zirconium alloy cladding tubes is of paramount importance for applications in nuclear reactors. Stress rupture properties of recrystallized Zircaloy-4 alloy were evaluated using burst testing of closed-end thin-walled tubing at varied test temperatures and internal pressures. The rupture data are correlated using the Larson-Miller parameter. The uniform circumferential elongations were also measured from which the hoop creep rates were calculated. These results were fitted to Monkman-Grant relationship with the aim of extrapolating the data to in-service stress levels. Furthermore, the creep data were plotted according to the Dorn equation where a transition in deformation mechanism from ‘power-law’ to ‘power law breakdown’ for Zircaloy-4 was noted. TEM studies corroborated the transition in mechanism from the power-law regime to a power-law breakdown regime.}, booktitle={Proceedings of 16th International Conference on Nuclear Engineering-Volume 1}, publisher={New York, NY: ASME}, author={Marple, B. and Song, Y. J. and Gollapudi, S. and Murty, K. L. and Charit, I.}, year={2008}, pages={385–388} } @article{murty_charit_2008, title={Structural materials for Gen-IV nuclear reactors: Challenges and opportunities}, volume={383}, ISSN={["0022-3115"]}, DOI={10.1016/j.jnucmat.2008.08.044}, abstractNote={Generation-IV reactor design concepts envisioned thus far cater toward a common goal of providing safer, longer lasting, proliferation-resistant and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-IV reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses and extremely corrosive environment, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This paper presents a summary of various Gen-IV reactor concepts, with emphasis on the structural materials issues depending on the specific application areas. This paper also discusses the challenges involved in using the existing materials under both service and off-normal conditions. Tasks become increasingly complex due to the operation of various fundamental phenomena like radiation-induced segregation, radiation-enhanced diffusion, precipitation, interactions between impurity elements and radiation-produced defects, swelling, helium generation and so forth. Further, high temperature capability (e.g. creep properties) of these materials is a critical, performance-limiting factor. It is demonstrated that novel alloy and microstructural design approaches coupled with new materials processing and fabrication techniques may mitigate the challenges, and the optimum system performance may be achieved under much demanding conditions.}, number={1-2}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Murty, K. L. and Charit, I.}, year={2008}, month={Dec}, pages={189–195} } @article{srikant_marple_charit_murty_2007, title={Characterization of stress rupture behavior of cornmercial-purity-Ti via burst testing}, volume={463}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2006.06.145}, abstractNote={Abstract An understanding of the stress rupture behavior of Ti alloy tubing is of primary importance for structural applications in energy technology. The stress rupture properties were evaluated using burst testing of closed-end, thin-walled tubing at varied test temperatures and internal pressures. The rupture data are correlated using the Larson–Miller parameter. The uniform hoop strains were also measured along with rupture times from which the strain-rates were calculated. These results were fitted to Monkman–Grant relation with the aim of extrapolating to in-service stress levels. The activation energy for creep deformation was calculated from the Arrhenius equation, and the experimental data were analyzed using Dorn parameters. The analysis indicated a transition from a power-law controlled creep regime to power-law breakdown at high stresses. Transmission electron microscopy studies corroborated the transition in mechanism from power-law region to a power-law breakdown region.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Srikant, G. and Marple, B. and Charit, I. and Murty, K. L.}, year={2007}, month={Aug}, pages={203–207} } @article{charit_murty_2008, title={Creep behavior of niobium-modified zirconium alloys}, volume={374}, ISSN={["0022-3115"]}, DOI={10.1016/j.jnucmat.2007.08.019}, abstractNote={Zirconium (Zr) alloys remain as the main cladding materials in most water reactors. Historically, a series of Zircaloys were developed, and two versions, Zircaloy-2 and -4, are still employed in many reactors. The recent trend is to use the Nb-modified zirconium alloys as the Nb addition improves cladding performance in various ways, most significant being superior long term corrosion resistance. Hence, new alloys with Nb additions have recently been developed, such as Zirlo™2 and M5™3. Although it is known that creep properties improve, there have been very few data available to precisely evaluate the creep characteristics of new commercial alloys. However, the creep behavior of many Nb-modified zirconium alloys has been studied in several occasions. In this study, we have collected the creep data of these Nb-modified alloys from the open literature as well as our own study over a wide range of stresses and temperatures. The data have been compared with those of conventional Zr and Zircaloys to determine the exact role Nb plays. It has been argued that Nb-modified zirconium alloys would behave as Class-A alloys (stress exponent of 3) with the Nb atoms forming solute atmospheres around dislocations and thus, impeding dislocation glide under suitable conditions. On the other hand, zirconium and Zircaloys behave as Class-M alloys with a stress exponent of ⩾4, attesting to the dislocation climb-controlled deformation mode.}, number={3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Charit, I. and Murty, K. L.}, year={2008}, month={Mar}, pages={354–363} } @article{guduru_wong_darling_koch_murty_scattergood_2007, title={Determination of Activation Volume in Nanocrystalline Cu Using the Shear Punch Test}, volume={9}, ISSN={1438-1656 1527-2648}, url={http://dx.doi.org/10.1002/adem.200700181}, DOI={10.1002/adem.200700181}, abstractNote={The mechanical behavior of nanocrystalline metals has been a research topic of interest for the past two decades. The current understanding is summarized in several recent reviews. Researchers have been investigating the deformation mechanisms in nanocrystalline metals and alloys through experimental and modeling routes. Modeling results indicate that there is a transition from dislocation generation at sources within grains to grain-boundary mediated dislocation generation in the grain size range between about 100 to 10 nm. Below 10 nm, grain boundary deformation modes (sliding, rotation, etc.) become dominant and inverse Hall-Petch effects have been reported. Experimental evidence to confirm these predictions is an active area of research. Two important experimental parameters that are useful in characterizing the deformation kinetics of materials are the strain rate sensitivity m and the activation volume V*. 11, 12] These are related by m = kT/V*r where k is Boltzmann’s constant, T is temperature (K) and r is the stress. There is a limited amount of data available on m and V* measurements for nanocrystalline metals. 5, 11–14] One aspect of this is the fact that research-scale synthesizing techniques often produce small quantities of material and mechanical testing procedures suited to small sample sizes are required. 5, 7, 13–18] In addition to this fact there is a tremendous scarcity of testing methodologies for testing the materials at small scales such as Micro-Electro-Mechanical-Systems (MEMS) where micro tensile and nanoindentation tests are used for understanding the deformation behaviour. 20] The aim of the present work was to extend the shear punch test (SPT) technique to the measurement of activation volumes on small scale specimens of few millimeters (∼ 1 mm to 3 mm). The advantage of SPT over nanoindentation and micro tensile tests is the deformation zone where a large number of grains undergo deformation within the shear zone and overcomes the problem of strain gradient plasticity effects, gain size effects as well as the specimen size effects. The SPT has been used for evaluating the yield and ultimate stress by numerous researchers, including us. The SPT shear yield or ultimate strength value s can be correlated with its tensile test counterpart r using the relation r = as. The correlation factor a depends upon the testing setup and data analysis methods. The Von Mises (VM) yield criterion predicts a = 3 if the SPT approximates pure shear loading conditions. This was the case in where the details and standardization of the SPT technique used in the present research work are given. The stress relaxation method has been used to determine activation volumes and dislocation dynamics in coarse-grain metals and alloys and in nanocrystalline Ni. The tests are normally done using uniaxial loading conditions. In the present study, we use the stress relaxation method in conjunction with the SPT technique. As far as we are aware, this is the first time that the full implementation of this method has been reported.}, number={10}, journal={Advanced Engineering Materials}, publisher={Wiley}, author={Guduru, R. K. and Wong, P. Z. and Darling, K. A. and Koch, C. C. and Murty, K. L. and Scattergood, R. O.}, year={2007}, month={Oct}, pages={855–859} } @article{guduru_murty_youssef_scattergood_koch_2007, title={Mechanical behavior of nanocrystalline copper}, volume={463}, ISSN={0921-5093}, url={http://dx.doi.org/10.1016/j.msea.2006.07.165}, DOI={10.1016/j.msea.2006.07.165}, abstractNote={The mechanical behavior of nanocrystalline materials has been studied extensively for the past few years. Recent studies on artifact-free materials with nanosize grains less than 100 nm have been very fruitful. These nanograined metals have exhibited very high strengths with reasonably good ductility. While there have been a large number of studies on hardness and strength characteristics, studies on strain rate sensitivity (SRS) are very limited. We describe here some of our recent work in characterizing SRS as well as activation volumes of nanograined copper using different testing procedures. These tests have been carried out under iso-strain rate and iso-structural conditions.}, number={1-2}, journal={Materials Science and Engineering: A}, publisher={Elsevier BV}, author={Guduru, Ramesh K. and Murty, K. Linga and Youssef, Khaled M. and Scattergood, Ronald O. and Koch, Carl C.}, year={2007}, month={Aug}, pages={14–21} } @article{guduru_darling_scattergood_koch_murty_2007, title={Mechanical properties of electrodeposited nanocrystalline copper using tensile and shear punch tests}, volume={42}, ISSN={["0022-2461"]}, DOI={10.1007/s10853-006-1095-3}, number={14}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Guduru, Ramesh Kumar and Darling, Kristopher A. and Scattergood, Ronald O. and Koch, Carl C. and Murty, K. L.}, year={2007}, month={Jul}, pages={5581–5588} } @article{murty_mansur_simonen_bajaj_2007, title={Proceedings of the Symposium on Radiation Effects, Deformation and Phase Transformations in Metals and Ceramics, Organized in Honor of Prof. Monroe S. Wechsler - TMS Annual Meeting, San Antonio, Texas, USA 12-16 March 2006 - Preface}, volume={361}, ISSN={["0022-3115"]}, DOI={10.1016/j.jnucmat.2006.12.002}, abstractNote={Microstructures developed in commercial 15-5 PH precipitation-hardened stainless steel after different heat treatments have been studied. In the as received condition, two types of carbides, NbC and M7C3, were present. Age hardening involves initial formation of fine precipitates rich in copper. Conventional transmission electron microscopy (TEM) and high resolution electron microscopy (HREM) studies have revealed the formation of a 9R structure copper precipitates (4 nm) in the samples aged at temperatures below 500 °C. However, at higher temperatures, in addition to the formation of these precipitates, the austenite phase was formed. After ageing at 500 °C for 128 h, M23C6 carbides were observed. The majority of the M23C6 carbides were in the interface of martensitic matrix and retained austenite. A second type of copper precipitate being, spherical in shape, were observed on ageing at 650 °C. TEM and X-ray microanalysis on thin foils and on carbon extraction replicas used for analysing the structure and metallic compounds of these precipitates. The mechanical properties following strain deformation has been carried out using scanning electron microscope (SEM), TEM and HREM. At peak aged, the 15-5 PH alloy exhibit brittle failure, the major fracture mode was cleavage and/or quasicleavage.}, number={2-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Murty, Korukonda L. and Mansur, Louis K. and Simonen, Edward P. and Bajaj, Ram}, year={2007}, month={Apr}, pages={VII-IX} } @article{charit_seok_murty_2007, title={Synergistic effects of interstitial impurities and radiation defects on mechanical characteristics of ferritic steels}, volume={361}, ISSN={["0022-3115"]}, DOI={10.1016/j.jnucmat.2006.12.003}, abstractNote={Ferritic steels are generally used in pressure vessels and various reactor support structures in light water reactors. They are known to exhibit radiation embrittlement in terms of decreased toughness and increased ductile–brittle transition temperature as a result of exposure to neutron radiation. The superimposed effects of strain aging due to interstitial impurity atoms on radiation embrittlement were considered first by Wechsler, Hall and others. Here we summarize some of our efforts on the investigation of synergistic effects between interstitial impurity atoms (IIAs) and radiation-induced point defects, which result in interesting effects at appropriate temperature and strain rate conditions. Two materials, a mild steel and a pressure vessel steel (A516 Gr.70), are evaluated using tensile and three-point bend tests.}, number={2-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Charit, I. and Seok, C. S. and Murty, K. L.}, year={2007}, month={Apr}, pages={262–273} } @article{koch_scattergood_murty_2007, title={The mechanical behavior of multiphase nanocrystalline materials}, volume={59}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-007-0042-3}, number={3}, journal={JOM}, author={Koch, Carl C. and Scattergood, Ronald O. and Murty, K. L.}, year={2007}, month={Mar}, pages={66–70} } @article{guduru_nagasekhar_scattergood_koch_murty_2007, title={Thickness and clearance effects in shear punch testing}, volume={9}, ISSN={["1438-1656"]}, DOI={10.1002/adem.200600255}, abstractNote={Shear punch testing (SPT) is a miniaturized specimen testing technique and is often used to predict the tensile properties of metals and alloys by testing a small amount of material. In order to rationalize the testing methodology it is necessary to understand the effect of different testing procedure parameters such as specimen thickness and die-punch clearance on the evaluated mechanical properties. We present our understanding of the above parameters on the SPT yield strength using finite element modeling studies in conjunction with our previous experimental results.}, number={3}, journal={ADVANCED ENGINEERING MATERIALS}, author={Guduru, Ramesh K. and Nagasekhar, Anumalasetty V. and Scattergood, Ronald O. and Koch, Carl C. and Murty, Korukonda L.}, year={2007}, month={Mar}, pages={157–160} } @article{murty_charit_2007, title={WITHDRAWN: Structural materials for Gen-IV nuclear reactors: Challenges and opportunities}, ISSN={0022-3115}, url={http://dx.doi.org/10.1016/j.jnucmat.2007.09.029}, DOI={10.1016/j.jnucmat.2007.09.029}, abstractNote={This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.}, journal={Journal of Nuclear Materials}, publisher={Elsevier BV}, author={Murty, K.L. and Charit, I.}, year={2007}, month={Oct} } @article{rajulapati_scattergood_murty_duscher_koch_2006, title={Effect of Pb on the mechanical properties of nanocrystalline Al}, volume={55}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2006.03.051}, abstractNote={Nanocrystalline (nc) Al–Pb two phase mixtures of different Pb concentrations were made by two different routes using high energy ball milling. The microhardness measurements show a softening in nc Al–Pb composites with the increase in Pb content, contradicting the previous results reported in the literature. We conclude that interaction of Pb atoms with nanocrystalline Al grain boundaries is responsible for the softening of the nc Al matrix observed in the current study.}, number={2}, journal={SCRIPTA MATERIALIA}, author={Rajulapati, Koteswararao V. and Scattergood, Ronald O. and Murty, Korukonda L. and Duscher, Gerd and Koch, Carl C.}, year={2006}, month={Jul}, pages={155–158} } @article{guduru_nagasekhar_scattergood_koch_murty_2006, title={Finite element analysis of a shear punch test}, volume={37A}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-006-0092-0}, number={5}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Guduru, R. K. and Nagasekhar, A. V. and Scattergood, R. O. and Koch, C. C. and Murty, K. L.}, year={2006}, month={May}, pages={1477–1483} } @article{guduru_scattergood_koch_murty_guruswamy_mccarter_2006, title={Mechanical properties of nanocrystalline Fe-Pb and Fe-Al2O3}, volume={54}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2006.02.014}, abstractNote={Fe, Fe–Al2O3, and Fe–Pb nanocrystalline alloys were prepared using ball milling. Fe–Al2O3 forms a nanocomposite and rule-of-mixtures hardening occurs with an additional contribution due to grain size reduction during milling. Fe–Pb forms a non-equilibrium solid solution where hardening appears to be modulated by Pb clustering and segregation to grain boundaries.}, number={11}, journal={SCRIPTA MATERIALIA}, author={Guduru, RK and Scattergood, RO and Koch, CC and Murty, KL and Guruswamy, S and McCarter, MK}, year={2006}, month={Jun}, pages={1879–1883} } @article{youssef_scattergood_murty_koch_2006, title={Nanocrystalline Al-Mg alloy with ultrahigh strength and good ductility}, volume={54}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2005.09.028}, abstractNote={A bulk nanocrystalline Al–5%Mg alloy was synthesized by an in situ consolidation mechanical alloying technique. The mechanical behavior of this alloy was investigated by hardness and tensile tests, which revealed it has four times the strength of a conventional Al-5083 alloy along with good ductility (8.5% elongation). The microstructure was investigated by X-ray diffraction and transmission electron microscopy, and the fracture surface by scanning electron microscopy.}, number={2}, journal={SCRIPTA MATERIALIA}, author={Youssef, KM and Scattergood, RO and Murty, KL and Koch, CC}, year={2006}, month={Jan}, pages={251–256} } @article{guduru_darling_scattergood_koch_murty_bakkal_shih_2006, title={Shear punch tests for a bulk metallic glass}, volume={14}, ISSN={["1879-0216"]}, DOI={10.1016/j.intermet.2006.01.052}, abstractNote={A shear punch test technique was used for characterization of the mechanical properties of Zr–5Ti–17.9Cu–14.6Ni–10Al bulk metallic glass. The ultimate shear stress values matched very closely with values derived from uniaxial compression tests reported in the literature. This is consistent with a lack of pressure sensitivity in compression reported for this particular metallic glass. Deformation response was strain rate insensitive up to a critical rate, beyond which softening occurred. The latter was attributed to thermal heating effects.}, number={12}, journal={INTERMETALLICS}, author={Guduru, R. K. and Darling, K. A. and Scattergood, R. O. and Koch, C. C. and Murty, K. L. and Bakkal, M. and Shih, A. J.}, year={2006}, month={Dec}, pages={1411–1416} } @misc{murty_charit_2006, title={Texture development and anisotropic deformation of zircaloys}, volume={48}, ISSN={["0149-1970"]}, DOI={10.1016/j.pnucene.2005.09.011}, abstractNote={This paper is a review of the texture development in zirconium alloys (in the form of thick walled tube reduced extrusion or TREX, thin-walled tubing and sheets) of importance to light and heavy water nuclear reactor technology along with the resultant anisotropic mechanical properties. Quantitative characterization of texture and mechanical anisotropy are emphasized leading to procedures useful to fabricators in optimizing textures for good formability as well as for acceptable in-service performance. A brief history of the development of zirconium alloys is presented followed by texture development and characterization. Mechanical anisotropy is discussed in terms of transverse contractile strain ratios from which the formability (B parameter) is derived. Results on the effect of annealing temperature as well as test temperature on anisotropy parameters are presented. The review concludes with a brief summary of texture effects on creep, stress corrosion cracking and hydride formation. Recent advances in fuel cladding bring out the challenges in characterizing the texture and anisotropy due to Nb additions and microstructural gradients in the new Zircaloys™, 1 such as Zirlo™, 2, Duplex™, 3 and Triclad ™, 4.}, number={4}, journal={PROGRESS IN NUCLEAR ENERGY}, author={Murty, KL and Charit, I}, year={2006}, pages={325–359} } @article{trichy_scattergood_koch_murty_2005, title={Ball indentation tests for a Zr-based bulk metallic glass}, volume={53}, ISSN={["1872-8456"]}, DOI={10.1016/j.scriptamat.2005.08.010}, abstractNote={Zr52.5Ti5Cu17.9Ni14.6Al10 bulk metallic glass was characterized using ball indentation tests. Comparison of the data with the expanding cavity model revealed that the deformation is pressure insensitive for compressive loading. The plastic flow curves obtained from indentation tests showed perfectly plastic response and no strain rate sensitivity up to 15% strain.}, number={12}, journal={SCRIPTA MATERIALIA}, author={Trichy, GR and Scattergood, RO and Koch, CC and Murty, KL}, year={2005}, month={Dec}, pages={1461–1465} } @article{koch_youssef_scattergood_murty_2005, title={Breakthroughs in Optimization of Mechanical Properties of Nanostructured Metals and Alloys}, volume={7}, ISSN={1438-1656 1527-2648}, url={http://dx.doi.org/10.1002/adem.200500094}, DOI={10.1002/adem.200500094}, abstractNote={AbstractWhile nanocrystalline metals can have strength and hardness values factors of 10 or more greater than their conventional grain size counterparts, ductility in tension has been disappointing, typically less than 2% elongation. This paper reviews the limitations to ductility in nanocrystalline materials and presents the results of recent breakthroughs wherein both high strength and good ductility are observed.}, number={9}, journal={Advanced Engineering Materials}, publisher={Wiley}, author={Koch, C. C. and Youssef, K. M. and Scattergood, R. O. and Murty, K. L.}, year={2005}, month={Sep}, pages={787–794} } @article{koch_youssef_scattergood_murty_2005, title={Breakthroughs in optimization of mechanical properties of nanostructured metals and alloys}, volume={7}, DOI={10.1002/adern.200500094}, number={9}, journal={Advanced Engineering Materials}, author={Koch, C. C. and Youssef, K. M. and Scattergood, R. O. and Murty, K. L.}, year={2005}, pages={787–794} } @article{mathew_yang_movva_murty_2005, title={Creep deformation characteristics of tin and tin-based electronic solder alloys}, volume={36}, ISSN={1073-5623 1543-1940}, url={http://dx.doi.org/10.1007/s11661-005-0142-z}, DOI={10.1007/s11661-005-0142-z}, number={1}, journal={Metallurgical and Materials Transactions A}, publisher={Springer Science and Business Media LLC}, author={Mathew, M. D. and Yang, H. and Movva, S. and Murty, K. L.}, year={2005}, month={Jan}, pages={99–105} } @inbook{murty_kishore_yan_scattergood_helsel_2005, title={Effect of annealing temperature on texture and creep anisotropy in Ti3Al2.5V alloy}, volume={495-497}, DOI={10.4028/www.scientific.net/msf.495-497.1645}, abstractNote={Effect of annealing temperature is investigated on texture and creep anisotropy in a thinwalled tubing of titanium alloy. Creep anisotropy is studied under equibiaxial loading using internally pressurized tubing superimposed with axial load while monitoring in-situ the time variations of both hoop and axial strains. Relatively weak hoop direction in the cold-worked material became stronger following complete recrystallization. The analyses of the data reveal that the anisotropy parameter, P which is the contractile strain ratio for testing along hoop direction increases from around 0.6 for the cold-worked material to around 1.5 following complete recrystallization. Results indicate that planar isotropy should occur following annealing at around 800K. Work on the effects of annealing on the textures and deformation microstructures is in progress. We summarize here results from some of our earlier work on a different lot of Ti3Al2.5V tubing in the recrystallized states where the ODFs were used in conjunction with crystal slip models to predict creep anisotropy.}, booktitle={Textures of materials: ICOTOM 14: Proceedings of the 14th International Conference on Textures of Materials, held in Leuven, Belgium, July 11-15, 2005 / Paul van Houtte; Leo Kestens. Uetikon-Zuerich, Switzerland ; Enfield, NH: Trans Tech Publications, 2005. (Materials science forum ; 495-497)}, publisher={Utikon-Zurich, Switzerland: Trans Tech Publications}, author={Murty, K. L. and Kishore, R. and Yan, J. and Scattergood, R. O. and Helsel, A. W.}, year={2005}, pages={1645–1650} } @article{murty_dentel_britt_2005, title={Effect of temperature on transitions in creep mechanisms in class-A alloys}, volume={410}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2005.08.006}, abstractNote={Alloy class materials exhibit viscous glide controlled creep, where dislocations are locked by solute atoms thereby decreasing their glide velocity while dislocation annihilation by climb still occurs. The creep-rate here varies as cube of the applied stress (stress exponent, n = 3) while the activation energy for creep becomes equal to that for solute atom diffusion. At high enough stress, the dislocations get freed from solute atom locking and transition to climb controlled creep is noted with n ∼ 5 while at still higher stresses, power-law breakdown is observed. For relatively small grain-sizes, viscous creep mechanisms such as Nabarro–Herring or Coble creep usually occur at low stresses. A close examination of the model equations reveals that at temperatures below a critical temperature, a transition from diffusional viscous creep to dislocation climb occurs without the intermediate viscous glide creep. Recent experimental results on a Zr–Nb sheet clearly follow these formulations exhibiting narrower intermediate region with decreasing temperature.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Murty, KL and Dentel, G and Britt, J}, year={2005}, month={Nov}, pages={28–31} } @article{guduru_darling_kishore_scattergood_koch_murty_2005, title={Evaluation of mechanical properties using shear–punch testing}, volume={395}, ISSN={0921-5093}, url={http://dx.doi.org/10.1016/j.msea.2004.12.048}, DOI={10.1016/j.msea.2004.12.048}, abstractNote={The evaluation of mechanical properties like yield and ultimate tensile strengths from shear–punch tests is important when the availability of material is limited. A shear–punch test setup was built in our laboratory and the mechanical properties for different materials; mild steel, pure Al, Zn, brass (Cu–30% Zn by wt.), Al 6061, Austenitic and Martensitic stainless steels were evaluated. A new method using 1% offset criterion in conjunction with normalized shear–punch curves was used to measure the shear yield strength. A linear correlation between the shear data and tensile data was established for yield and ultimate strengths. The variation of the yield and ultimate shear strength was studied as a function of the sample thickness and die–punch clearance for soft, medium and high strength materials.}, number={1-2}, journal={Materials Science and Engineering: A}, publisher={Elsevier BV}, author={Guduru, R.K. and Darling, K.A. and Kishore, R. and Scattergood, R.O. and Koch, C.C. and Murty, K.L.}, year={2005}, month={Mar}, pages={307–314} } @article{seok_bae_koo_murty_2006, title={The properties of the ring and burst creep of ZIRLO cladding}, volume={13}, ISSN={["1873-1961"]}, DOI={10.1016/j.engfailanal.2005.02.009}, abstractNote={Cladding is used as a separator between fuel and coolant and a container of fuel in nuclear reactors. The cladding is the first part to break in accidents like LOCA or RIA in nuclear plant. Knowledge of the fracture characteristics of cladding is indispensable for the safe operation of nuclear plants. The objective of this study is to evaluate the creep properties of nuclear cladding using the ring tensile specimen. This study consists of two parts: ring and burst creep test. From the results of the ring tensile tests arid numerical analyses, the load–displacement conversion relationship for the ring specimen (LCRR) at high temperatures was determined. LCRR was applied to obtain creep properties from ring creep tests. The results from the creep tests of ring specimens were compared with those from the burst creep tests of closed-end specimens, and the results showed an applicability of the creep test using the ring specimen instead of burst creep test for evaluating the creep properties of the cladding.}, number={3}, journal={ENGINEERING FAILURE ANALYSIS}, author={Seok, CS and Bae, BK and Koo, JM and Murty, KL}, year={2006}, month={Apr}, pages={389–397} } @article{youssef_scattergood_murty_horton_koch_2005, title={Ultrahigh strength and high ductility of bulk nanocrystalline copper}, volume={87}, ISSN={["1077-3118"]}, DOI={10.1063/1.2034122}, abstractNote={We have synthesized artifact-free bulk nanocrystalline copper samples with a narrow grain size distribution (mean grain size of 23nm) that exhibited tensile yield strength about 11 times higher than that of conventional coarse-grained copper, while retaining a 14% uniform tensile elongation. In situ dynamic straining transmission electron microscope observations of the nanocrystalline copper are also reported, which showed individual dislocation motion and dislocation pile-ups. This suggests a dislocation-controlled deformation mechanism that allows for the high strain hardening observed. Trapped dislocations are observed in the individual nanograins.}, number={9}, journal={APPLIED PHYSICS LETTERS}, author={Youssef, KM and Scattergood, RO and Murty, KL and Horton, JA and Koch, CC}, year={2005}, month={Aug} } @article{murty_mathew_2004, title={Nondestructive monitoring of structural materials using automated ball indentation (ABI) technique}, volume={228}, ISSN={["1872-759X"]}, DOI={10.1016/j.nucengdes.2003.06.006}, abstractNote={Materials used for high temperature components in nuclear power generation, aerospace, chemical and process plants undergo changes in their microstructure during operation in service leading to degradation in their mechanical properties. Monitoring the progressive changes in the mechanical properties is very important from the point of view of ensuring the structural integrity of the components and also for possible extension of their useful service life. Nondestructive methods for directly evaluating the mechanical properties are required for the success of any materials aging and life management program. In this paper, we describe an innovative automated technique based on ball indentation that can be used for laboratory and field applications in order to measure the mechanical and fracture properties of materials. Typical results from laboratory studies on engineering materials are also presented.}, number={1-3}, journal={NUCLEAR ENGINEERING AND DESIGN}, author={Murty, KL and Mathew, MD}, year={2004}, month={Mar}, pages={81–96} } @article{youssef_scattergood_murty_koch_2004, title={Ultratough nanocrystalline copper with a narrow grain size distribution}, volume={85}, ISSN={["1077-3118"]}, DOI={10.1063/1.1779342}, abstractNote={We report a unique way of using mechanical milling/in situ consolidation at both liquid-nitrogen and room temperature to produce artifact-free nanocrystalline Cu(23nm) with a narrow grain size distribution. This nanocrystalline Cu exhibits an extraordinarily high yield strength (770MPa), as predicted from a Hall–Petch extrapolation, along with good ductility (comparable with ∼30% uniform tensile elongation). Possible factors leading to this excellent optimization of strength and ductility are discussed.}, number={6}, journal={APPLIED PHYSICS LETTERS}, author={Youssef, KM and Scattergood, RO and Murty, KL and Koch, CC}, year={2004}, month={Aug}, pages={929–931} } @article{zhou_devarajan_murty_2004, title={Short-term rupture studies of Zircaloy-4 and Nb-modified Zircaloy-4 tubing using closed-end internal pressurization}, volume={228}, ISSN={0029-5493}, url={http://dx.doi.org/10.1016/j.nucengdes.2003.06.013}, DOI={10.1016/j.nucengdes.2003.06.013}, abstractNote={Burst rupture properties of Zircaloy-4 and Nb-Modified Zircaloy-4 are investigated at temperatures ranging from 638 to 843 K by internal pressurization of closed-end tubing samples. Various pressurization levels were imposed and rupture times were noted. The data enabled an evaluation of Larson–Miller parameter and the present experimental results on Zircaloy-4 were in excellent agreement with those reported in the literature. The effect of 1% Nb addition to Zircaloy-4 was studied since these materials are now known to resist long-time corrosion in water reactors and are thus considered for high burn-up applications. Negligible differences were noted in the rupture characteristics between the standard Zircaloy-4 and Nb-added Zircaloy-4. In addition, a limited amount of testing was performed to characterize the hoop creep behavior of these materials using a creep tester with hoop strain monitored in situ by a Laser telemetric extensometer. Both the alloys followed an exponential stress variation of the creep-rate at high (>10−3E, E is the elastic modulus) stresses. At very low stresses, viscous creep was noted identifiable with Coble creep corresponding to small grain sized materials.}, number={1-3}, journal={Nuclear Engineering and Design}, publisher={Elsevier BV}, author={Zhou, Y and Devarajan, B and Murty, K.L}, year={2004}, month={Mar}, pages={3–13} } @article{rao_godavarti_mahmood_murty_2002, title={Plastic instability and mechanical anisotropy of textured zinc}, volume={30}, number={3}, journal={Journal of Testing and Evaluation}, author={Rao, G. S. S. and Godavarti, P. S. and Mahmood, S. T. and Murty, K. L.}, year={2002}, month={May}, pages={197–207} } @article{murty_seok_2001, title={Fracture in ferritic reactor steel - Dynamic strain aging and cyclic loading}, volume={53}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-001-0082-z}, number={7}, journal={JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY}, author={Murty, KL and Seok, CC}, year={2001}, month={Jul}, pages={23–26} } @article{edsinger_murty_2001, title={LWR pellet-cladding interactions: Materials solutions to SCC}, volume={53}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-001-0079-7}, number={7}, journal={JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY}, author={Edsinger, K and Murty, KL}, year={2001}, month={Jul}, pages={9–13} } @article{murty_2001, title={Materials issues in light water reactors}, volume={53}, number={7}, journal={JOM: the Journal of the Minerals, Metals & Materials Society}, author={Murty, K. L.}, year={2001}, month={Jul}, pages={88} } @article{murty_2000, title={Deformation mechanisms and transients in creep of zircaloys: Applications to nuclear technology}, volume={53}, number={3}, journal={Transactions of the Indian Institute of Metals}, author={Murty, K. L.}, year={2000}, month={Jun}, pages={107–120} } @article{mathew_yang_movva_murty_2000, title={High temperature deformation characteristics of tin-based solder alloys: Application to electronic packaging}, volume={53}, number={3}, journal={Transactions of the Indian Institute of Metals}, author={Mathew, M. D. and Yang, H. and Movva, S. and Murty, K. L.}, year={2000}, month={Jun}, pages={369–379} } @article{yim_murty_2000, title={Materials issues in nuclear-waste management}, volume={52}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-000-0183-0}, number={9}, journal={JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY}, author={Yim, MS and Murty, KL}, year={2000}, month={Sep}, pages={26–29} } @article{murty_2000, title={The internal pressurization creep of Zr alloys for spent-fuel dry storage feasibility}, volume={52}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-000-0185-y}, number={9}, journal={JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY}, author={Murty, KL}, year={2000}, month={Sep}, pages={34–38} } @article{mathew_murty_rao_mannan_1999, title={Ball indentation studies on the effect of aging on mechanical behavior of alloy 625}, volume={264}, ISSN={["0921-5093"]}, DOI={10.1016/s0921-5093(98)01098-3}, abstractNote={The effect of aging on mechanical behavior of Alloy 625 was investigated using the non-destructive Stress–Strain Microprobe (SSM) system. SSM is based on an automated ball indentation (ABI) technique, and involves multiple indentations by a small spherical indenter at a single penetration location under strain-controlled conditions. The technique permits evaluation of mechanical properties such as yield strength, ultimate tensile strength, strength coefficient and strain hardening exponent. Alloy 625 was aged at six different temperatures in the range of 873–1173 K for 500 h each. ABI tests were carried out at room temperature and at 473 K. The variation of yield and ultimate tensile strengths with aging temperature exhibited a peak in strength following aging at 973 K. The peak stress was 1.5 times the strength of the unaged material, and the strength after aging at 1173 K was nearly equal to that of the unaged material. The peak in strength is attributed to the precipitation of the γ” phase. The fall in strength due to aging above 973 K is attributed to the precipitation, growth and dissolution of δ-phase precipitates. These studies demonstrate that ABI can be used as a non-destructive technique to determine changes in mechanical properties of nickel base alloy components due to aging.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Mathew, MD and Murty, KL and Rao, KBS and Mannan, SL}, year={1999}, month={May}, pages={159–166} } @article{murty_miraglia_mathew_shah_haggag_1999, title={Characterization of gradients in mechanical properties of SA-533B steel welds using ball indentation}, volume={76}, ISSN={["0308-0161"]}, DOI={10.1016/S0308-0161(99)00006-X}, abstractNote={Gradients in mechanical and fracture properties of SA-533B steel welds were studied using ball indentation technique. The local stress–strain behaviors of different microstructural zones of the weld were determined at various temperatures. Gradients in the strength of the base metal, weld metal and the different positions in the heat affected zone were observed to be consistent with the changes in the microstructure. The maximum in yield and the corresponding minimum in indentation energy to fracture occurred at around 1 mm from the fusion line.}, number={6}, journal={INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING}, author={Murty, KL and Miraglia, PQ and Mathew, MD and Shah, VN and Haggag, FM}, year={1999}, month={May}, pages={361–369} } @article{murty_1999, title={Creep studies for Zircaloy life prediction in water reactors}, volume={51}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-999-0184-6}, number={10}, journal={JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY}, author={Murty, KL}, year={1999}, month={Oct}, pages={32–39} } @article{mathew_movva_murty_2000, title={Deformation mechanisms in tin and tin-based electronic solder alloys}, volume={171-1}, ISBN={["0-87849-842-7"]}, ISSN={["1013-9826"]}, DOI={10.4028/www.scientific.net/kem.171-174.655}, journal={CREEP AND FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES}, author={Mathew, MD and Movva, S and Murty, KL}, year={2000}, pages={655–662} } @article{seok_murty_1999, title={Effect of dynamic strain aging on mechanical and fracture properties of A516Gr70 steel}, volume={76}, ISSN={["0308-0161"]}, DOI={10.1016/S0308-0161(99)00075-7}, abstractNote={The effects of dynamic strain aging (DSA) on mechanical and fracture characteristics were investigated in a ferritic steel type A516Gr70 commonly used for reactor support steels and pressure vessels. Tensile and 3-point bend tests were performed on miniature tensile and subsize Charpy specimens at various temperatures from ambient to about 700 K with specific purpose of delineating the friction and source hardening terms, and the effects of DSA on them. The total energy to fracture obtained from the areas under the load–displacement curves of 3-point bend tests of subsize Charpy specimens revealed dips in the DSA range. Unloading compliance JIC tests were performed on 1TCT specimens at varied temperatures from 243 (−30) to about 773 K (500°C) using a clip gauge (T<400K) and a high-temperature extensometer. At temperatures higher than 273 K valid JIC measurements could be made and JIC decreased with increasing temperature. However, no dips in the DSA range were noted contrary to the earlier observations in A533B steel and pure iron. Effect of neutron radiation exposure was investigated on the mechanical properties using subsize tensile and 3-point bend specimens. Synergistic effects of interstitial impurities and radiation-induced defects resulted in shifting the region of DSA to higher temperatures revealing improved ductility in some temperature regimes following radiation exposure.}, number={14-15}, journal={INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING}, author={Seok, CS and Murty, KL}, year={1999}, month={Dec}, pages={945–953} } @article{mathew_lietzan_murty_shah_1999, title={Low temperature aging embrittlement of CF-8 stainless steel}, volume={269}, ISSN={["1873-4936"]}, DOI={10.1016/s0921-5093(99)00140-9}, abstractNote={Cast stainless steels such as CF-8 are used for several components such as pump and valve casings, elbows, fittings and primary coolant pipes in nuclear power plants. CF-8 stainless steel has a duplex microstructure consisting of austenite and about 15–20% δ-ferrite. Long-term exposure at the reactor operating temperatures results in aging-induced embrittlement of the material due to spinodal decomposition of the ferrite phase. In this paper, we report the effects of low temperature aging (673 K) up to 18 months on the mechanical and fracture properties of cast CF-8 stainless steel in the range of 173–423 K. These studies have been carried out using non-destructive ball indentation tests. Standard Charpy and tensile tests were also carried out to complement the ball indentation data. Increase in strength and decrease in toughness have been observed following aging. These changes in the properties tend to saturate on aging for more than 12 months.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Mathew, MD and Lietzan, LM and Murty, KL and Shah, VN}, year={1999}, month={Aug}, pages={186–196} } @article{mathew_murty_1999, title={Non-destructive studies on tensile and fracture properties of molybdenum at low temperatures (148 to 423 K)}, volume={34}, ISSN={["0022-2461"]}, DOI={10.1023/A:1004547709783}, number={7}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Mathew, MD and Murty, KL}, year={1999}, month={Apr}, pages={1497–1503} } @article{murty_1999, title={Role and significance of source hardening in radiation embrittlement of iron and ferritic steels}, volume={270}, ISSN={["0022-3115"]}, DOI={10.1016/S0022-3115(98)00766-1}, abstractNote={Radiation effects on ferritic steels used for pressure vessels and pure iron are investigated to examine the role of the source hardening term responsible for the yield point phenomena and dynamic strain-aging (DSA). The majority of the radiation hardening stems from friction hardening, and the source hardening term decreased with exposure to neutron radiation apparently due to the interaction of the interstitial impurities with radiation produced defects. This decrease in the source hardening suppressed DSA which in turn led to increased ductility with a simultaneous increase in the strength in the temperature range of DSA in the unirradiated condition. While the source hardening term was evaluated from an extrapolation of the work-hardening region to the elastic line for the ferritic steels, the grain-size variation of the yield strength in pure iron allowed a direct evaluation and demonstrated their equivalence. The influence of low-energy (Cd-cutoff) neutrons was studied by comparing radiation effects in specimens with and without Cd-wrapping. Inclusion of thermal neutrons along with fast resulted in a small decrease in the source hardening with a slight increase in the friction hardening which revealed a critical grain size below which exposure to total (fast and thermal) neutron spectrum resulted in a slight reduction in the yield stress compared to the exposure to only fast neutrons. This grain-size effect is shown to be in line with known radiation effects on friction and source hardening terms along with the observation that low-energy neutrons have a non-negligible effect on the mechanical properties of steels. In ferritic steels, however, despite their small grain size, exposure to total neutron spectrum yielded higher strengths than exposure to only fast neutrons. This behavior is consistent with the fact that the source hardening is small in these alloys and the radiation effect is due only to friction stress.}, number={1-2}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Murty, KL}, year={1999}, month={Apr}, pages={115–128} } @article{murty_mathew_haggag_1998, title={An investigation of the deformation mechanisms in Sn5%Sb alloy using tensile, creep and ABI tests from ambient to 473K}, volume={4}, ISSN={["1225-9438"]}, DOI={10.1007/bf03026401}, number={4}, journal={METALS AND MATERIALS-KOREA}, author={Murty, KL and Mathew, MD and Haggag, FM}, year={1998}, pages={799–802} } @article{malow_koch_miraglia_murty_1998, title={Compressive mechanical behavior of nanocrystalline Fe investigated with an automated ball indentation technique}, volume={252}, ISSN={["0921-5093"]}, DOI={10.1016/s0921-5093(98)00661-3}, abstractNote={Nanocrystalline (nc) iron was produced by mechanical attrition and compacted into near fully dense samples. Isothermal annealing at 800 K resulted in grain sizes between 15 and 24 nm. A newly available Automated Ball Indentation system was used to study the compressive mechanical properties of the samples. The ABI method proved useful in examining the mechanical properties of nc iron on a more quantitative level than previously possible by conventional hardness testing methods. Stress–strain curves were obtained which indicated a compressive behavior similar to that of perfectly plastic materials: low strain hardening at high flow stresses around 3 GPa and a low room-temperature strain-rate sensitivity. The flow stresses were independent of the grain size in the range of the present study. The deformation pile-up around the indentations seems to have formed inhomogeneously, exhibiting intense plastic deformation in localized shear bands.}, number={1}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Malow, TR and Koch, CC and Miraglia, PQ and Murty, KL}, year={1998}, month={Aug}, pages={36–43} } @article{wang_murty_1998, title={Effect of temperature on mechanical anisotropy of Zircaloy-4 sheet}, volume={4}, ISSN={["1225-9438"]}, DOI={10.1007/bf03026387}, number={4}, journal={METALS AND MATERIALS-KOREA}, author={Wang, Y and Murty, KL}, year={1998}, pages={723–726} } @article{murty_detemple_kanert_dehosson_1998, title={In-situ nuclear magnetic resonance investigation of strain, temperature, and strain-rate variations of deformation-induced vacancy concentration in aluminum}, volume={29}, ISSN={["1543-1940"]}, DOI={10.1007/s11661-998-0168-0}, abstractNote={Critical strain to serrated flow in solid solution alloys exhibiting dynamic strain aging (DSA) or Portevin-LeChatelier effect is due to the strain-induced vacancy production. Nuclear magnetic resonance (NMR) techniques can be used to monitor in situ the dynamical behavior of point and line defects in materials during deformation, and these techniques are nondestructive and noninvasive. The new CUT-sequence pulse method allowed an accurate evaluation of the strain-enhanced vacancy diffusion and, thus, the excess vacancy concentration during deformation as a function of strain, strain rate, and temperature. Due to skin effect problems in metals at high frequencies, thin foils of Al were used and experimental results correlated with models based on vacancy production through mechanical work (vs thermal jogs), while in situ annealing of excess vacancies is noted at high temperatures. These correlations made it feasible to obtain explicit dependencies of the strain-induced vacancy concentration on test variables such as the strain, strain rate, and temperature. These studies clearly reveal the power and utility of these NMR techniques in the determination of deformation-induced vacancies in situ in a noninvasive fashion.}, number={1}, journal={METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE}, author={Murty, KL and Detemple, K and Kanert, O and Dehosson, JTM}, year={1998}, month={Jan}, pages={153–159} } @article{haggag_byun_hong_miraglia_murty_1998, title={Indentation-Energy-to-Fracture (IEF) parameter for characterization of DBTT in carbon steels using nondestructive Automated Ball Indentation (ABI) technique}, volume={38}, number={4}, journal={Scripta Materialia}, author={Haggag, F. M. and Byun, T. S. and Hong, J. H. and Miraglia, P. Q. and Murty, K. L.}, year={1998}, pages={645–651} } @article{murty_mathew_wang_shah_haggag_1998, title={Nondestructive determination of tensile properties and fracture toughness of cold worked A36 steel}, volume={75}, ISSN={["0308-0161"]}, DOI={10.1016/S0308-0161(98)00093-3}, abstractNote={Tensile and fracture properties of ASTM grade A36 steel have been studied using nondestructive Stress–Strain Microprobe™ system (SSM), which is developed on the basis of automated ball indentation (ABI) technique. Tests have been carried out on as-received, and cold worked (4, 8 and 12%) materials at several temperatures in the range −150°C–+200°C at a constant strain rate. Tensile properties determined from ABI tests agreed well with the results from conventional tensile tests. The elastic–plastic fracture toughness parameter KJC was estimated from the ABI data. As expected, cold working resulted in increase in strength, decrease in fracture toughness and increase in ductile to brittle transition temperature. ABI is a reliable nondestructive technique for determining tensile and fracture properties of materials and has potential applications in the nuclear industry particularly to determine toughness degradation due to aging in service.}, number={11}, journal={INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING}, author={Murty, KL and Mathew, MD and Wang, Y and Shah, VN and Haggag, FM}, year={1998}, month={Sep}, pages={831–840} } @article{ghosh_kang_murty_notis_1998, title={Special issue on interfacial reactions, solid state transformations and thermal management - Foreword}, volume={27}, ISSN={["0361-5235"]}, DOI={10.1007/s11664-998-0061-z}, number={11}, journal={JOURNAL OF ELECTRONIC MATERIALS}, author={Ghosh, G and Kang, S and Murty, KL and Notis, M}, year={1998}, month={Nov}, pages={1137–1137} } @article{murty_haggag_mahidhara_1997, title={Tensile, creep, and ABI tests on Sn5%Sb solder for mechanical property evaluation}, volume={26}, ISSN={["1543-186X"]}, DOI={10.1007/s11664-997-0260-z}, number={7}, journal={JOURNAL OF ELECTRONIC MATERIALS}, author={Murty, KL and Haggag, FM and Mahidhara, RK}, year={1997}, month={Jul}, pages={839–846} } @article{murty_1997, title={Zircaloy life prediction and new generation zircaloys for LWRs}, volume={50}, number={6}, journal={Transactions of the Indian Institute of Metals}, author={Murty, K. L.}, year={1997}, pages={533–562} } @book{murty_charit, title={An introduction to nuclear materials: Fundamentals and applications}, publisher={Weinheim, Germany: Wiley-VCH}, author={Murty, K. L. and Charit, I.} } @inproceedings{wang_luan_murty_liu, title={Effect of Mo and Bi additions on the microstructure of Zr-Cr-Fe alloy after beta-quenching}, booktitle={Mechanical and creep behavior of advanced materials}, author={Wang, J. M. and Luan, B. F. and Murty, K. L. and Liu, Q.}, pages={183–192} } @inproceedings{murty, title={Effect of c/a-ratio on crystallographic texture and mechanical anisotropy of hexagonal close packed metals}, volume={426-4}, number={2003}, booktitle={Thermec 2003: International Conference on Processing and Manufacturing of Advanced Materials (Materials science forum ; v. 426-432).}, publisher={Uetikon-Zurich, Switzerland: Sci-Tech Pub. Ltd.; Enfield, N.H.: Trans Tech Pub. Ltd.}, author={Murty, K. L.}, pages={3575–3580} } @inproceedings{sarkar_alsabbagh_murty, title={Effect of low dose neutron irradiation on tensile behavior of ht-9 steel at room temperature}, booktitle={TMS 2014 Supplemental Proceedings}, author={Sarkar, A. and Alsabbagh, A. H. and Murty, K. L.}, pages={147–154} } @misc{roodposhti_sarkar_murty_scattergood, title={Effects of microstructure and processing methods on creep behavior of AZ91 magnesium alloy}, volume={25}, number={9}, journal={Journal of Materials Engineering and Performance}, author={Roodposhti, P. S. and Sarkar, A. and Murty, K. L. and Scattergood, R. O.}, pages={3697–3709} } @inproceedings{roodposhti_murty, title={Fracture behavior and grain boundary sliding during high-temperature low-stress deformation of AZ31 magnesium alloy}, booktitle={Mechanical and creep behavior of advanced materials}, author={Roodposhti, P. S. and Murty, K. L.}, pages={279–287} } @inbook{murty_detemple_k._dehosson, title={In-situ NMR investigation of strain, temperature and strain-rate variations of deformation-induced vacancy concentration in aluminum}, ISBN={0873393430}, booktitle={Nondestructive evaluation and material properties III}, publisher={Warrendale, Pa.: Minerals, Metals & Materials Society}, author={Murty, K. L. and Detemple, K and K. and Dehosson, J.}, editor={P. K. Liaw, O. Buck and R. J. Arsenault and Green, R. E., Jr.Editors} } @inproceedings{gollapudi_bhosle_charit_murty, title={Low stress viscous creep in a ti-3al-2.5v tubing under internal pressurization}, booktitle={TMS 2010 139th Annual Meeting & Exhibition - Supplemental Proceedings, vol 1: Materials processing and properties}, author={Gollapudi, S. and Bhosle, V. and Charit, I. and Murty, K. L.}, pages={755–762} } @article{roodposhti_sarkar_murty, title={Microstructural approach to equal channel angular processing of commercially pure titanium-A review}, volume={25}, number={5}, journal={Transactions of Nonferrous Metals Society of China}, author={Roodposhti, P. S. and Sarkar, N. F. A. and Murty, K. L.}, pages={1353–1366} } @article{charit_murty, title={structural materials issues for the next generation fission reactors}, volume={62}, number={9}, journal={JOM: the Journal of the Minerals, Metals & Materials Society}, author={Charit, I. and Murty, K. L.}, pages={67–74} }